• TABLE OF CONTENTS
HIDE
 Front Cover
 Title Page
 Front Matter
 Table of Contents
 Index
 Main
 Back Cover






Title: Weeds of Florida
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00000989/00001
 Material Information
Title: Weeds of Florida
Series Title: Report - University of Florida Cooperative Extension Service ; SP-37
Physical Description: Book
Language: English
Creator: Hall, David W.
Vandiver, Vernon V. Jr.
Dolbier, Joyce ( Editor )
Publisher: Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 1994
 Record Information
Bibliographic ID: UF00000989
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: ltqf - AAA0064
ltuf - AME7141
alephbibnum - 002441928
 Related Items
Other version: Alternate version (PALMM)
PALMM Version

Table of Contents
    Front Cover
        Page i
        Page ii
    Title Page
        Page iii
    Front Matter
        Page iv
    Table of Contents
        Page v
        Page vi
        Page vii
        Page viii
        Page ix
    Index
        Page x
        Page xi
        Page xii
    Main
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
        Page 47
    Back Cover
        Page 48
Full Text




(P~


'I~


I







r. vi W.Hl
opS O





in














Weeds of Florida


David W. Hall
and
Vernon V. Vandiver, Jr.


David W. Hall is an Extension Botanist in the Herbarium with IFAS, University of Florida and Florida Museum of
Natural History, Gainesville. Vernon V. Vandiver, Jr, is an Associate Professor and Aquatic Weeds Scientist, Fort
Lauderdale Research and Education Center, IFAS, University of Florida.



































Editor:
Graphic Designer:
Cover Art & Layout:


Joyce J. Dolbier
Ron Stephens
Helen Huseman


Copyright University of Florida, Institute of Food and Agricultural Sciences, 1994

Parts of this publication may be reproduced for educational use. Please provide credit to the "University
of Florida, Institute of Food and Agricultural Sciences," accompanied by the published date.









Contents
Introd auction ................... .................................... ...... ............. v ii
Illustrated Glossary ................ ......... ....... ................... ........... ix
Index ................................................................. x
W eeds ................... ...................................... .. ....... 1













Introduction

Weed growth of both native and exotic vegetation can severely decrease the commercial, recrea-
tional and aesthetic value of crops, landscapes and waterways. In certain situations some degree of
weed growth may be desirable. Control measures are needed only when an overabundance of
weed growth begins to affect economic use. Our environment is a complex and dynamic system
that is subject to a myriad of pressures. This is particularly true of Florida which has undergone
tremendous demographic growth in the last decade. With the continuously increasing demand for
Florida's resources, it is essential that they be managed in the most prudent fashion. Because of
Florida's geographical setting and meteorological conditions, much of the state supports an exten-
sive growth of weeds, many of which are not found in other parts of the United States.
This publication is designed as an aid to the identification of weeds found in Florida. Modern
methods of weed management require that a correct name be applied to the weed so that appro-
priate control measures can be taken. Biology and history are included as an aid in adapting control
measures and research involving these species. The use of integrated programs may be more
efficient than the use of any single weed control method. While this publication is specifically
directed toward the professional, it can be used by everyone. Identification of the plants is aided by
the color photographs which are placed with the text.
Eventually all of the more than 600 weeds in Florida will be documented in this way. The weeds
are arranged alphabetically by the scientific name.
The scientific name used is that found in the Composite List of Weeds published in Weed Science,
Volume 32, Supplement 2, pages 1-137, 1984. Some names have not yet been included in this
listing. The Florida common name for the plant is always listed first followed by the common name
(if different) found in the above volume of Weed Science. The scientific and common names for the
family are included in addition to any alternate scientific name for the family (in parentheses).















Illustrated Glossary


TYPICAL FLOWER

Corolla (petals)
Calyx (sepals)

Receptacle


Peduncle




COMPOUND LEAF


Peduncle


UMBEL


DICOT LEAVES


illary Bud


DICOT SEEDLING (BEAN)


Foliaae Leaves


Roots


Cotyledons


Hypocotyl


Primary Root


Botanical Artist: Suzanne McCullough


ix












Index

Abrus precatorius L. .. .............. . . . . . . .
Acanthospermum hispidum DC. ................................. 2
Bagpod . . . . . . . . . . . . . . . . . . . . . . . 42
Balsam-apple.. ......... ....... ................... ...... 31
Bean, Precatory ............. ... .. ......... ............. . I
Beggar's-tick
Com m on . . ... . .. . .. . . . . . . ...... . . . .... . 4
Hairy . . . . . . . . . . . .. .. . . . .. ... .. . .. 4
Betony, Florida . . . . . . . . . . . . . . . . . . . . 45
Bidens alba (L.) DC ....... ... .... ...... .. ...... ..... ... ..... 4
Black M edic.. . . .. . . . . . . .. . .. . . . . . . . . . 28
Bladderpod . . . . . . . . .. . . . . . . . . . . . 42
Brazil Pusley . . . . . . . . . . . . . . . . . . . . . . 36
Brazilian Pepper-tree. ........................... . . . . . 40
Bristly Starbur.. ................................. . . . . . 2
Carolina Geranium... ........................ . . . . . . 18
Cassia fasciculata Michx. ................... . . . . . . ...... 5
Cassia obtusifolia L. ................... ....... ..... . . . ... 6
Cassia occidentalis L. . .... ............ .. ....... .... .. . . . 8
Catclaw M imosa ............................. . . . . . . 29
Cenchrus echinatus L. .................... . . . . . 9
Cenchrus incertus Curtis .. ... ................... . . . .. 10
Chenopodium album L. ........ ......... ...... . . . . . . 11
Chenopodium ambrosioides L .... . ................ . . . . . 12
C itron . . . . . . . . . . . .. .. . . . . . . . . . . 13
Citron Melon.... .................. . . . . . . . . . . 13
Citrullus lanatus (Thunb.) Mats. & Nakai ............... . . . . . . 13
Coast Sandspur .. ........ .... .......... .. ..... .. .... . 10
Coffee Senna................... ................. ........ .... 8
Common Beggar's-tick. .................... . . . . . . 4
Common Lamb's-quarters ....................... . . . . . . .
Creeping W ood Sorrel .................... . . . . . . 32
Curly Dock . . . . . . . .. . . . .. .. . . . . . . . 38
Cutleaf Ground-cherry ........ . . ................ . . 34
Cyperus esculentus L . . ........................... . . . 14
Cyperus rotundus L ......................... . . . . . . 16
Cypress-vine Morning-glory ..................... . . . . . . . 24
Datura stramonium ......... . . . ... ... .......... ........ 17
Dock, Curly... ...... . . . . . .... ................ ........ 38
East Indian Hygrophila. ............................. . . .. . 20
Field Sandbur .... ........ ............ ...... . 10
Florida Betony . . . . . . . . . . . . . . . . . . . . . 45
Florida Pusley . . . . . . . . . . . . . . . . . . . . . 37









Geranium carolinianum L. ............... ......................... 18
G eranium Carolina . . . . . .... . . . . . . .. . .. . .. . . 18
Giant Sensitive Plant ............. .... ... ....................... 29
Ground-cherry, Cutleaf ............. .......................... .. 34
Hairy Beggar's-tick ...................... . . . . . ...... 4
Heartwing Sorrel... .. ............................... . . . 39
Hemp Sesbania .............................. . . . . . 43
Horse-nettle ....................... . . . . . ...... 44
H yd rilla . . . . . . . . . . . . . . . . . . . . . . . . 19
Hydrilla verticillata (L. f.) Presl ................... . . . . . . 19
Hygrophila polysperma (Roxb.) T. Anderson ............. . . . . . 20
Hygrophila, East Indian .................... . . . . . . 20
Ipomoea hederifolia L. .......................... . . . . . 22
Ipomoea lacunosa L ........................... . . . . . 23
Ipomoea quamoclit L. ......................... . . . . . . 24
Ipomoea trichocarpa Ell ................. . . . . . . . ...... 25
Jacquemontia tamnifolia (L.) Griseb.. .................. . . . . . 26
Jimson Weed. ............ . ...... . . . . . . 17
Lamb's-quarters.... .......................... . . . . . . 11
Lamb's-quarters, Common ................... .. ... . . . .. 11
Lim nophila . . . . . . . . . . . . . . . . . . . . . . 27
Limnophila sessiliflora (Vahl) Blume ........... .......... . . . . . .27
Maypop ....... . . . . ...... .... ............. ....... 33
M edic, Black . . . . . . ...... . . . . . . . . .. . .. 28
Medicago lupulina L................... . . . . . . ...... . . 28
Melon, Citron .............................. . . . . . 13
M exican-tea .. . . . . . . . . . . . . . . . . . ..12
M imosa pigra L. . . . . . . . . . . . . . . . . . . . . ...... 29
Mimosa, Catclaw. ................... . ...... . . . . . . ..29
M omordica charantia L. ......... . . . . . . . . . . . . . . . 31
Morning-glory
Cypress-vine . . . . . ....................... . . . ...... 24
Pitted . . . . . . . . . . . . . . . . . . . . . ... 2 3
Scarlet .. .. . . . . . . . . . . . . . . . . . . . . . 22
Sharp-pod ....................... . . . . . ...... 25
Small-flower.. .............. . . . . . . . . . ...... 26
Nutsedge
Purple ....... .............. . . . ......... ......... 16
Yellow . . . . . . . . . . . . . . . . . . . . . . . 14
Oxalis corniculata L. ................... . ....... . . . . . . 32
Oxalis florida Salisb . . . . . . . . . . . . . . . . . . .. 32
Partridge Pea ........ .............. . . . . . . . ...... 5
Passiflora incarnata L. ........... . .............. . . . . . ... 33
Passion-flow er . . . . . . . . . . . . . . . . . . . . ...... 33
Pea
Partridge. .... ......... ..... . . . . . . . . . . . 5
Rosary . . . . . . .. . . . . . . . . .. . . . .



xi









Pepper-tree, Brazilian. .. ......................... . . . . . 40
Physalis angulata L...... .............. .......... ...... ..... 34
Pitted Morning-glory. ........................... . . . . . 23
Precatory Bean ........................ ......... . . . . . .
Purple Nutsedge. .... ............ ................. . . . 16
Pusley
Brazil ............ .............. . . . . ........ 36
Florida ...... . . ..... . . . . . . . .. . . .. 37
Radish, W ild .. . . . . . . .... . . . . . . . . . . .. 35
Raphanus raphanistrum L ....................... . . . . . . . 35
Richardia brasiliensis (Moq.) Gomez ............... . . . . . . . 36
Richardia scabra L . . .............................. . . ...... 37
Rosary Pea . . . . . . . . . . . . . . . . . . ... . . .
Rumex crispus L ................... . . . ....... . . ...... 38
Rumex hastatulus Baldwin ex Ell. ................... ...... . . . ... .39
Sandbur
Field ..... . .... . . . . 10
Southern ................. .... . . . . . . ...... . . 9
Sandspur
C oast . . . . . . . . . . . . . . . . . . 10
Southern ..... ..... . ...... . . . . ...... .... 9
Scarlet Morning-glory .. ..................... . . . . . . 22
Schinus terebinthifolius Raddi ................... . . . . . . 440
Senna, C coffee . . . . . . . . . . .. . . . . . . .. . . . . 8
Sensitive Plant, Giant. ................... .. ...... . . . . ...... 29
Sesbania exaltata (Raf.) Cory ...................... . . . 43
Sesbania macrocarpa Muhl. ...................... . . . . . . 43
Sesbania vesicaria (Jacq.) Ell. . . ......... .............. . . . 42
Sesbania, Hemp. ................ . ........... . . . . . ...... 43
Sharp-pod Morning-glory .................... . . . . . . 25
Sicklepod .. .. .... ... .. .... . . . . . . .. ... .. . 6
Small-flower Morning-glory .................. . ...... . . . . 226
Solanum carolinense L. . . . ........................ . . . . 44
Sorrel, Heartw ing . . . . .. . . . . . . .. . . . .. . . . . ...... 39
Southern Sandbur .. . . . ........... .. ... ...... . . . . . . 9
Southern Sandspur. ................................ . . . . 9
Southern Yellow Wood Sorrel ......... .. . . . ....... . . . . 332
Stachys floridana Shuttlew ........................... . . . . 45
Starbur, Bristly . . . . . . . . . . . . . . . . . . . . . . 2
W ild Radish . . . . . . . . . . . . . . . . . . . . ... 35
Wood Sorrel
Creeping ....... . . . ..... . .............. ........ 32
Southern Yellow . . . . . . . . . . . . . . . . . . 32
Yellow Nutsedge ..... . . . . . . . . . . . . . . . . . . 14









Rosary Pea

(Precatory Bean)
Abrus precatorius L.
Leguminosae (Fabaceae)
Bean Family













Photograph: Ted J. Stelter
Mature Plant Habitat
This perennial, climbing vine is This weed is established in
woody in southern Florida to ornamental plantings, land-
somewhat herbaceous in cen- scapes and waste grounds in
tral Florida. It branches freely southern and central Florida,
and can reach a height of ap- the West Indies, Mexico and
proximately 6.5 meters. The South America.
leaves are alternate, measuring 01


3.3 to 11.5 cm, ana are com-
pound, having 8 to 20 pairs of
leaflets. The leaflets are oblong
with rounded ends that come
to a point and measure 0.3 to
2.1 cm in length and 2 to 8.2
mm wide. The purple, pink or
white flowers are crowded on
a stalk measuring 3 to 6 cm.
The fruit, a flat, broad, rectangu-
lar pod, measures 2.3 to 4.0 cm
in length. Each pod contains 3
to 5 seeds that are scarlet with
a black spot at the point of
attachment. The pod splits
when dried, revealing the cling-
ing seeds.
History
The Greek word abrus means
delicate and refers to the leaf-
lets. Precatorius is Latin for one
who prays and alludes to the
use of the seeds for rosaries.


All parts of this plant are toxic,
especially the seeds, which are
highly toxic.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/ University of Florida/1989


Photograph: Ted J., Stelter
Seedling
The cotyledons are oval and the
first true leaves are compound.










Bristly

Starbur
Acanthospermum hispidum DC.
Compositae (Asteraceae)
Sunflower Family


Photograph: Wayne L. Currey

Mature Plant
Bristly Starbur is an upright
annual with dichotomous
(Y-shaped) branching. The
Y-shaped form of branching
gives the plant one of its com-
mon names, Slingshot Weed.
The stems are densely covered
with hairs. These hairs can be
stiff and bristly or soft and
flexible. The leaves have no
stalk (sessile) and are opposite
each other on the stem. They
are oval to triangular-ovate in
shape with a base that narrows
rapidly to the stem. Some leaves
can be up to 11.5 cm long. The
margins of the leaves can have
irregular teeth or they may be
entire and smooth. Like the
stems, the leaves are hairy The
hairs are on both the upper
and lower surfaces and on the
margins. The lower leaf surface
is also dotted with glands. The
flowers are typical of the Aster
or Daisy Family Each head has
5 to 9 ray flowers. The petals
(corollas) of the ray flowers are
pale yellow and are about 1.5
mm long. The disc flowers in
the center of the head are
sterile. The fruits are flattened
and triangular in shape. These
fruits are covered with stiff,
hooked hairs and have either a


straight or curved pair of spines
at the top. The bristly appear-
ance and grouping of several
fruits in each head provides the
most frequently used common
name, Bristly Starbur. Each fruit,
excluding the terminal spines, is
5 to 6 mm long. The terminal
spines are strongly divergent
and are about 4 mm long.
These terminal spines supply
yet an additional common
name, Goathead.

History
Bristly Starbur appears to have
been introduced into Florida in
ship ballast at Pensacola in the
1800s. The scientific name of
the genus, Acanthospermum, is
from the Greek words acantha
(thorn) and sperma (seed) and
refers to the prickly fruit. His-
pidum is Latin, and means
rough, shaggy, prickly or bristly.
Habitat
This weed is currently a prob-
lem in southern Alabama, south-
ern Georgia, northern Florida,
and appears to be spreading
southward in Florida. In the
rest of the United States it has
been reported as far north as
New Jersey, again in ballast
grounds. It occurs in Central


Photograph: Ted J. Stelter
Seedling
The cotyledons are broadly club
shaped and wavy margined.
The first leaves are oval to trian-
gular, Irregularly and coarsely
toothed, light green In color
and very broad.


Ir_ _ ~_









and South America from Hon-
duras and Nicaragua, south-
ward to Argentia. This weed
has become naturalized in
Africa, the Hawaiian Islands,
India, Australia and the West
Indies.

Biology
No use is known for this plant.
It is not used for forage and
has been found toxic to mice
and goats. The hooked hairs of
the fruit attach easily to the
coats of animals, and the fruit
is widely distributed by this
means. In Florida the weed
causes problems in corn,
peanuts and soybeans by com-
peting for moisture, light and
nutrients. Also, the weed can
be a physical problem during
harvest as it continues to grow
until a killing frost.
This noxious weed is a prolific
seed producer. Plants only 25


cm in height are capable of
producing mature seeds. The
seeds are produced in abun-
dance until the plants freeze in
the fall. In one study, an aver-
age yield of over 4500 kg/ha of
seeds was obtained. The germi-
nation of harvested seeds is
around 10 percent, but soaking
them alone in water or KNO3
increases germination to 60
percent and, when coupled
with chilling, increases germina-
tion to 80 percent. Soaking
seeds with scarified seed coats
improves germination by 80 to
90 percent. One study showed
that scarification by pre-freez-
ing, acid or sandpaper reduced
germination by 50 to 80 per-
cent. Another study showed
seed viability to be only 36
percent indicating an immature
embryo. Thus the dormancy of
these seeds seems to be due to
the following combination of


factors: immature embryo;
impermeable seed coat; and
substances inhibiting germina-
tion. Since seeds fall from the
plant very soon after maturing,
most of them that remain on
the plant at harvest are imma-
ture and result in low germina-
tion when tested in the labora-
tory This may lead to an errone-
ous conclusion about natural
populations. Seeds buried in
soil below 7.5 cm have been
shown to lose all viability after
three years. Plowing of seeds
to a greater depth could be a
help in reducing occurrence of
this pest.
Preliminary results suggest that
Bristly Starbur is quite competi-
tive. Studies on population
thresholds and period of com-
petition are underway in Florida
and Alabama.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlverslty of Florida/1989









Common

Beggar's-tick
(Hairy Beggar's-tick)
Bidens alba (L.) DC.
Compositae (Asteraceae)
Sunflower Family


Phoograpn willlam S Blomieey
Mature Plant
Common Beggar's-tick is an
annual or short-lived perennial
with a tap root and often roots
at lower nodes, with the stems
erect or bending at the base.
The opposite leaves are com-
pound, 2 to 10 cm long and 1
to 3.5 cm wide. The leaf edges
are toothed and the underside
of the leaf is hairy. The flowers
are daisy-like. The outer flowers
are petal-like white rays. The
flowers in the center form a
disc which has many small,
yellow flowers. The seeds are
4-angled and spindle shaped
with 2 to 6 sharp-pointed
projections at the top.
History
The Latin genus name Bidens
means two-toothed and refers
to the two projections usually
found at the top of the seed.
The Latin species name alba
means white and alludes to the
white flowers.
Habitat
This weed is common in turfs
and disturbed areas throughout
Florida. It is found virtually
everywhere in the subtropics
and tropics of both hemis-
pheres.


Biology
The seeds detach easily and
projections at the top cling to
passing animals. The seeds
germinate easily, but germina-
tion can be enhanced by slitting
the end. A plant produces an
average of 1,205 seeds.
-David W. Hall and Vernon V. Vandlver, Jr.
FAS/lnlvenlty of Florid/1989


Phoograph: John D. Tobe
Seedling
The cotyledons are linear with
the mldveln evident as a depres-
sion on the upper surface. The
first true leaves are opposite
and deeply cut into segments,
each being elliptic or nearly so
and opposite.










Partridge Pea

Cassia fascculata Michx.
Leguminosae (Fabaceae)
Bean Family


Photograph: Jon D.To~b
Mature Plant
Partridge Pea is a smooth or
hairy annual, 20 to 100 cm tall,
and arises from a tap root The
leaves have a distinct gland
midway along the stalk and are
compound. Each leaf has 12 to
36 linear leaflets which are I
to 3 cm long and 2 to 6 mm
wide. The sides of the leaflet
are usually of different widths.
The stipules have whitish veins
running parallel with the mid-
vein. The flowers are borne in
clusters of I to 6, in the leaf
axis. The flowers have yellow
petals and 10 unequal stamens.
The fruit is a smooth to hairy
bean, which is 3 to 7 cm long
and 5 to 7 mm broad. The
seeds are flat, dark brown and
about 0.3 cm wide.

History
Cassia is ancient Greek for a
particular aromatic plant The
Latin name fasciculata means
clustered and refers to the
flower and eventual fruit clus-
ters.

Habitat
This weed is found throughout
Florida in disturbed sandy soils.
The range extends throughout
the southeastern United States.


Biology
The flowers are a source of
honey. The seeds and leaves
are purgative. Large amounts
are thought to be harmful as
animals have been poisoned.
-DMd W. HU and Wmmon V Wnd, Jr.
iMS/Unw.vlty of r Foralda


Photograph: JohD.Tob
Seedling
The cotyledons are less than 1.0
cm long and about 0.5 cm
across, with 3 prominent mid-
veins and a red area where the
cotyledon Joins the stem.










Sicklepod

Cassia obtusifolia L
Leguminosae (Fabaceae)
Bean Family


mPhonp: Wurr L CMy


Mature Plant
Sicklepod is an annual with
erect, nearly hairless stems. The
leaves are compound with 3 to
10 leaflets and a conspicuous
gland about 2 mm long be-
tween, orjust above, the low-
est pair of leaflets. The terminal
pair of leaflets is frequently
larger than the lower pairs of
leaflets. The leaflet blades are
broader toward the tips and
smooth above and below. The
leaflet margins have short,
appressed hairs. Each leaflet
base is asymmetrical and the
leaflet tip is usually rounded
with a tiny sharp point. The
leaflets are also photosensitive.
(The leaflets fold upward by
flexible petioles at night or on
cloudy days.) The stipules are
hairy, linear and about 1 to 2
cm long. The flowers are axillary
and usually solitary with yellow
petals 8 to 17 mm long. The
petals are unequal in shape
and size. The sepals are un-
equal, 5 to 10 mm long and 2
to 5 mm wide. The fruit is a
slender pod up to 18 cm long,
5 mm wide, 4-angled in cross
section and usually curved
downward. The pods are green
and turn brown as the seeds


mature. The seeds are 4 to 6
mm long, angular, light to dark
brown in color, with 2 scars on
the opposite surfaces oriented
along the longest axis of the
seed. Hairs on the stem of C.
obtusifolla in the cotyledonary
stage distinguish it from C.
occidentalls In the mature
stage, they can be readily sepa-
rated by the leaf shape.

History
Cassia is ancient Greek for a
particular aromatic plant The
Latin word obtusifolia means
obtuse leaved and refers to the
leaf shape.

Habitat
C obtusifolia now occurs
throughout Florida and the
southeastern United States. It
is native to the tropical re-
gions of North, Central and
South America.

Biology
Seed germination occurs over a
temperature range of 18 to
36 C. Maximum germination
was obtained at 24 to 33* C
with alternating daily tempera-
ture treatment. Maximum


Pho.9r~W: W.y L Cury
Seedling
The cotyledons are rounded, 15
to 20 mm broad, green above
and light green below, with 3
to 5 distinct veins In the upper
surface Joining the mldveln. The
stem appears almost smooth
but Is covered with short, down-
ward-pointed hairs.









hypocotyl elongation occurred
at 300 C. Germination was
delayed by -3 bars osmotic
pressure while -6 bars reduced
96-hour-germination to 64
percent and 10 bars to 21
percent. Primary root length
was sharply reduced by simu-
lated drought. The ability to
germinate at relatively low soil
moisture levels and high seed
production may help account
for the rapid establishment of


this weed species. A single
plant can produce up to 8,000
seeds.
The hard seedcoat has been
found to inhibit germination.
Only 15 percent germination
could be obtained by incuba-
tion of unscarified seeds at
230 C for a year in moist soil.
Attempts to produce adventi-
tious roots and therefore veg-
etative regeneration of plants


from seedlings after cutting the
stems 1 cm below the cotyle-
dons failed.
As day and night temperatures
increased from 23/170 C to
29/230 C, plant height, leaf
area, total dry weight and
axillary branch leaf production
increased.
Seeds are known to be toxic to
some animals.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlverslty of Florlda/1989









Coffee Senna

Cassia occidentalis L.
Leguminosae (FabaceaeJ
Bean Family


*--


PnologiaDn rapne L Cinret

Mature Plant
Coffee Senna is 3 smccrm an-
nual Enat can De 2 m tail. The
leaves are compound. The
leaflets are in 4 to 6 pairs and
have a sharp leaf apex. These
leaflets are 2 to 9 cm long and
2 to 3 cm wide with a distinct
gland 3 to 5 mm from the base
of the stalk. Flowering occurs
in the leaf axils. The sepals are
green and 6 to 9 mm long. The
petals are yellow and I to 2
cm long. The 6 to 7 stamens
are of two different lengths.
The seed pods are dark brown,
8 to 12 cm long, 7 to 10 mm
wide and curve slightly upward.
The seeds are dull brown, 4 to
5 mm long and flattened on
both ends.

History
Cassia is ancient Greek for a
particular aromatic plant. The
Latin word occidentalis means
western, and refers to the
origin.

Habitat
C occidentalis is widespread in
warm areas of the world except
for Australasia.


Biology
On rtc datierent soil types
grown was greater me higher
the pH, 4.7 to 6.3.
The seeds are known to be
weakly toxic to various stock
animals. Animals normally avoid
ingesting these seeds.
Increased germination is ob-
tained by seed scarification.
-David W. Hall and Vernon V. Vandlver. Jr.
IFAS/Unlverslty of Florlda/1989


Photograph: Ted J. Stelter
Seedling
The cotyledons are smooth,
round, about 1 cm long, and
usually less than 1 cm wide
with 3 distinct veins In the
upper surface. The stems have
visible hairs Just above and
below the cotyledons.









Southern

Sandspur

(Southern Sandbur)

Cenchrus echinatus L.
Gramineae (Poaceae)
Grass Family


whMature : MkhMPlat

Mature Plant Habitat


Southern Sandspur is an annual
with ascending stem tips from
the lower nodes which bend
and root The leaf sheaths are
completely without hairs or
can have long hairs along the
margins. The blades lack hairs
above and below, or can have
long scattered hairs above. The
seedheads are composed of
spiny burs and are 3 to 14 cm
long and I to 2 cm wide. The
burs, excluding the spines, are
4.1 to 6.3 mm wide and 5.3 to
8.0 mm long to the tip of the
spikelets. The spines are of two
kinds: 1) flattened spines that
are spread over the body of
the bur and 2) fine slender
bristle-like spines that are
situated in a ring at the base of
the bur. The seedheads appear
throughout the year in the
South and during the summer
and fall in the North.

History
The name Cenchrus is from the
Greek word for millet, cenchros
The Greek species name
echinatus means armed with
spines.


This weed occurs throughout
Florida in turf, cultivated and
disturbed areas; throughout
warmer areas of the United
States, from North Carolina to
California; Mexico; Central
America; South America; the
West Indies; Pacific Islands; and
Australia.

Biology
The southeastern United States
has two similar weedy
sandspurs. These are Coast
Sandspur C. incertusJ and the
Southern Sandspur. Two kinds
of spines on the bur of the
Southern Sandspur separate it
from the Coast Sandspur.
-DvlAd W. Hall d Vron V. Vld, Jr.
iMfAunhntty of Flldalfti


hmotgraph: aomy R. Wllrd
Seedling
The blades are flat and like
sandpaper on the upper surface.
The ligules are up to 1.6 mm
long. The lower papery portion
of the Ilgule Is only 0.2 mm long
and the fringe of hairs Is up to
1.4 mm long.



































Coast Sandspur is an annual or
short-lived perennial. The stems
are erect or bend at the lower
nodes with the stem tips as-
cending. The leaf sheaths are
either hairy or bare. The blades
have a few scattered long hairs
on the upper surface and often
have scattered hairs at the
base of the otherwise nonhairy
lower surface. The seedheads
of spiny burs are 2 to 8.5 cm
wide and 4.1 to 7.0 mm long
to the tip of the spikelets. The
spines of only one kind are
flattened and spread over the
body of the bur. The seedheads
appear throughout the year.

History
The name Cenchrus is from the
Greek word for millet, cenchros.
The Latin species name incertus
means uncertain and probably
alludes to the problems
botanists have had with this
species.


This weed occurs throughout
Florida in dry, sandy, cultivated
and disturbed areas; warmer
parts of the United States from
Virginia to California; Mexico;
Central America; South America;
the West Indies; the Philippine
Islands; and South Africa.

Biology
The southeastern United States
has two similar weedy
sandspurs. These are the Coast
Sandspur and the Southern
Sandspur (C. echinatus). Only
one kind of spine on the bur of
the Coast Sandspur separates it
from the Southern Sandspur.
-David W. Hall and Vernon V. Vandiver, Jr.
IFAS/Unlverslty of Florida/1989


Photograph: Ted J. Stelter
Seedling
The blades are flat and like
sandpaper on the upper surface.
The Ilgules are up to 1.3 mm
long. The lower papery portion
of the Ilgule Is only 0.2 mm long
and the fringe of hairs Is up to
1.1 mm long.


Lli ~









Lamb's-

quarters

(Common Lamb's-
quarters)

Chenopodium album L.
Chenopodiaceae
Goosefoot Family


Photograph: A. W. Evans


Mature Plant
Lamb's-quarters is an erect, tap
rooted, summer annual. The
maximum height is about 2 m.
The entire plant is covered
with varying amounts of a
waxy substance giving the
plant a light green appearance.
The branches are angular or
ridged, ascending, and usually
striped with purple, pink or
yellow. The leaves are simple,
arranged alternately and are
variable in shape and size. They
may be up to 8 cm long. The
leaf blades are usually ovate to
lanceolate. The margins may or
may not be toothed and may
appear to be 3-lobed. Occa-
sional specimens have purple -
to wine-colored leaf bases. The
flowers are gray to green and
are arranged in spikes in the
leaf axils at the ends of the
branches and stems. The upper
flowering portion has few
leaves. The flowers are without
petals. The sepals are slightly to
sharply ridged, nearly covering
the mature fruit. The seeds are
disc shaped with a notch,
glossy black, brown or brown-
ish green, and 1.2 to 1.6 mm in
diameter. The seeds have a
thin, papery covering which
often persists, giving them a
dull appearance.


History
The Greek word chenopodium
means goose and foot, which
refers to the shape of the leaves
of some species. The Latin
species name album means
white and alludes to the waxy
covering on the plant.
Habitat
Lamb's-quarters is found
throughout the world from sea
level to 3,600 m in elevation
and from the latitudes 70 de-
grees N to 50 degrees S except
in extreme desert climates. It
occurs on disturbed sites and
thrives on all soil types and
over a wide range of soil pH
values.
Biology
Seed germination for this plant,
after evaluating seeds stored in
the ground, decreased over a
5.5-year-period from 96 percent
to 1 percent. Seed germination
was increased with the follow-
ing plant growth regulants:
GA3 (promoted germination to
over 96 percent), Thiourea
(promoted germination to over
95 percent), CEPA [(2-
chlorethyl-phosphonic acid)
increased germination to over
86 percent], NAA (promoted
germination to over 74 percent).


Photograph: Ted J. Stelter
Seedling
The cotyledons are narrowly
elliptic, about 1.2 to 1.5 cm long
and are dull green above and
purple on the lower surface.


The control used for all of the
preceding growth regulators
had a germination of 63 per-
cent. Physical treatments have
also proved to be effective
promoters of germination.
These are: temperature (at
400C for 120 minutes increased
germination to 92 percent) and
sonification (using a 1.25 cm
disruptor horn for 1 minute at
20 kc/sec increased germination
to 82 percent).
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlverslty of Florida/1989










Mexican-tea

Chenopodium ambrosioides L.
Chenopodiaceae
Goosefoot Family


Photograph: A. W. Evans


Mature Plant
Mexican-tea is a strong-scented
herb which may be annual or
perennial. Its growth can be
erect or ascending, up to 1 m
tall. The stems and branches
may be smooth or minutely
hairy. The leaves are alternate,
oblong to ovate or lanceolate
in shape, and contain varying
numbers of small dots which
are glands. The margins may be
wavy or toothed. The leaf size
is gradually reduced upward
on the plant. The flowers occur
in clusters on spikes, with the
upper spikes in a branched
arrangement. The leaves may
or may not be present on the
spikes. The calyx is about 1 mm
long, usually glandular, and
completely encloses the fruit
which is small, bladder-like and
1-seeded. The seeds are nearly
black, similar to C album but
smaller (0.6 to 0.8 mm in diame-
ter). Taxonomically, C am-
brosioides can be separated
from C album by the presence
of hairs or glands. C album can
be separated by the presence
of waxy particles which are
absent on C ambrosioides.


History
The Greek word chenopodium
means goose and foot, which
refers to the shape of the leaves
of some species. The Greek and
later Latin species name am-
brosioides means that this
plant resembles some species
of Ambrosia.

Habitat
This weed occurs in waste
areas, cultivated lands and
disturbed sites throughout
Florida northward to Maine
and Ontario and westward
from Florida to Texas and
California. This plant is native
to the West Indies, Mexico,
Central and South America and
is naturalized in Europe, Asia,
Africa and North America.

Biology
This plant has a very disagree-
able odor. It will bloom and
fruit when only 4 cm tall or
can reach its maximum height
of 1 m tall before flowering
and fruiting.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlversity of Florida/1989


Photograph: John D. Tobe

Seedling
The stem Is pink. The cotyledon
blades are ovate and green on
both surfaces, or tinged pink on
the lower surfaces. The first two
leaves are opposite, while the
subsequent leaves are alternate.


~I*









Citron

(Citron Melon)
Citrullus lanatus (Thunb.) Mats. &
Nakai
Cucurbitaceae
Cucumber Family


Photograph: Wayne L Currey

Mature Plant
Citron is a monoecious, hairy,
annual with a climbing or
sprawling growth habit. The
tendrils are borne to the side of
the deeply divided leaves. The
three to four pairs of lobes in
the leaves are mostly rounded
with toothed margins and a
rough surface. The flowers are
solitary, with the petals being
broad and yellow (2 to 10 mm
long). The flower tube is 2 to 5
mm long. The fruit is a many
seeded berry It may be light
green or be a variegated light
and dark green. The pulp is
hard with white flesh. The fruit
is globose to oblong and is 15
to 50 cm long. The seeds are
greenish with a pitted surface.

History
Citrullus is the diminutive of
the Greek word citrus which
refers to the fruit. The Latin
species name lanatus means
wooly and calls attention to
the hairs on the stems and
leaves.


Habitat
This weed is native to tropical
and warm temperate Africa. It
is found on sandy soils in waste
places, woods, pinelands, culti-
vated areas and roadsides from
Florida to Texas, northward to
North Carolina.

Biology
This weed is closely related to
the Watermelon which has the
same scientific name.
-David W. Hall and Vernon V. Vandlver. Jr.
IFAS/Unlversity of Florlda/1989


Photograph: lbd J. Stelter
Seedling
The cotyledons are thick, ovate,
and shiny green on the surface.
The distinctive white venation
Is obvious. The large cotyledons
are about 1.0 cm wide and 1.8
cm long. The first leaves are
palmate, or nearly so.


simmommomp . ...... .. .. .










Yellow

Nutsedge

Cyperus esculentus L.
Cyperaceae
Sedge Family


Photograph: Daniel L. Colvin


Mature Plant
Yellow Nutsedge is an erect
perennial sedge and has un-
branched stems which are solid
and triangular in cross section,
frequently growing up to 69
cm tall. It may reach a height
of 90 cm. The leafy shoot and
rhizomes originate from a basal
bulb formed by a swelling of
the stem below the soil surface.
Rhizomes growing out from
this basal bulb may produce
either secondary basal bulbs or
underground tubers. The leaves
have a prominent midvein and
are arranged in three ranks
growing from the basal half of
the stem. The newer leaves are
ascending and may be as long
as, or longer than, the stem.
The leaf width ranges from 2 to
15 mm. The inflorescence is
umbel-like, with up to 10 un-
equal stalks bearing few to
many spike-like branches of
flattened yellowish brown
spikelets. The spikelets are 1 to
2.8 cm long and 2 mm wide,
each spikelet consisting of
several flowers. The stalks may
be up to 18 cm long but are
frequently much smaller. The
modified leaves underneath the
inflorescence are variable in
number and size. The larger


modified leaves may be up to
30 cm long and 9 mm wide.
The fruit is enclosed in a thin
covering. It is broadest near
the apex and gradually tapers
to a narrow, rounded base. The
fruit is somewhat triangular in
cross section with 3 concave
sides. The surface of the cover-
ing has minute dimples. The
color of the fruit ranges from
light tan to dark brown.

History
The genus name Cyperus is
from Cypeiros which was the
ancient Greek name for the
genus. The Latin name escu-
lentus means edible, and refers
to the tubers.

Habitat
This weed is found throughout
Florida in scattered populations
and throughout the United
States. It occurs in all types of
disturbed areas.

Biology
Seed production is variable and
many stands do not produce
mature seeds. Seeds planted in
greenhouses or flats outside
have been germinated, but
there are no reports of seed-
lings in field situations. Some


rnotograpn: A. w. evans
Seedling
Two or three leaves emerge
from the ground simultaneously.
The blades are linear, folded
lengthwise, smooth, membra-
nous, light green, and overlap-
ping to form a somewhat trian-
gular structure In cross section.
The bud leaves are erect. The
sheaths are tubular.


- ---- --- --- ---- ---- --- --








germination is probably occur-
ring but is missed because the
numbers are so few. Plants
grow in a sigmoid pattern,
producing a new leaf every 4.5
to 5 days in the normal grow-
ing cycle. Leaf growth is rapid
for a short period of time;
within a week the growth
slows to an undetectable rate.
The total period of leaf growth
varies from 24 to 40 days. New
leaves progressively shorten
until the fourth or fifth leaf,
with subsequent leaves gradu-
ally becoming longer.
Tuber production is influenced
by substrate. Tubers planted in
sand emerged sooner than
those in sandy silt-loam, but


tubers in sandy silt-loam pro-
duced more plants (at the end
of a six-week period). Tubers
planted in peat produced the
most shoots per tuber both
initially and finally The tuber
epidermis contains one or more
substances that inhibit sprout-
ing of buds on tubers. Washing
tubers resulted in an increase
in sprouting of fall harvested
tubers. High nitrogen concen-
tration, long photoperiods and
high levels of G.A. inhibit tuber
formation. High temperatures
(27 and 330 C) coupled with
low nitrogen levels increased
tuber production. At high nitro-
gen levels and long photo-
periods (14 and 15.5 hours)


shoot formation was promoted.
High temperature favored
shoot formation at 12.5- and
14-hour photoperiods, while
G.A had an inhibitory effect.
Rhizomes differentiating into
new shoots increased with 18-
to 24-hour photoperiods. Tuber
formation diminished as photo-
period increased but number of
tubers produced at the end of
three months was unaffected.
This is due to the production of
new tubers from rhizome-
produced plants.
This plant tolerates high soil
moisture and is intolerant of
shade.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unversity of Florlda/1989










Purple

Nutsedge

Cyperus rotundus L.
Cyperaceae
Sedge Family


Photograph: Michael Riffle
Mature Plant
Purple Nutsedge is a smooth,
erect, perennial sedge. It has a
fibrous root system which is
extensively branched. The plant
spreads by means of slender
rhizomes. Its tubers are white
and succulent when young,
turning brown or black and
fibrous with age. The erect,
simple stems are smooth, solid
and triangular in cross section.
The stems are frequently up to
36 to 40 cm tall, occasionally
to 70 cm, and have been found
to reach 100 cm on moist fertile
soils. The leaves originate from
the base of the plant. They are
linear with sharp tips and may
be much shorter than, or as
long as, the culm is tall, and are
usually not more than 5 mm
wide. The leaves are smooth,
shiny, dark green and grooved
on the upper surface. The
seedhead consists of 3 to 8
unequal, slender, 3-sided stalks.
The red to purplish brown
spikelets are up to 3.5 cm long
and 2 mm wide and are clus-
tered at the ends of the stalks.
Each spikelet is made up of
from 10 to 40 individual flow-
ers. The fruit is 1.5 to 2 mm
long, 1.5 mm wide, triangular
in cross section, grayish brown
and dull. Both the apex and


the base of the fruit are
rounded. The seedhead is sub-
tended by 2 to 4 modified
leaves about as long as, or
shorter than, the seedhead.

History
The genus name Cyperus is
from Cypeiros which was the
ancient Greek name for the
genus. Rotundus is Latin for
round and refers to the tuber.

Habitat
C rotundus occurs in disturbed
areas throughout Florida and
the Southeastern United States.
It is widely distributed through-
out both the tropical and
warmer temperate regions of
the world.

Biology
Most of the success of this
troublesome weed is due to its
ability to survive and reproduce
from tubers during adverse
conditions. It grows well in
almost every soil type, over a
wide range of soil moisture, pH
and elevation, and can survive
the highest temperatures en-
countered in agriculture. It
does not tolerate shaded areas.
Temperature and shade seem
to be the most important fac-
tors in natural control of this


Seedling Photograph: Davd W. Hall
Two or three leaves emerge
from the ground simultaneously.
The blades are linear, folded
lengthwise, smooth, membra-
nous, light green, and overlap-
ping to form a somewhat trian-
gular structure In cross section.
The bud leaves are erect. The
sheaths are tubular.


weed. The plants also repro-
duce by seeds but this is negli-
gible since seed germination
seldom averages more than I
to 5 percent. The production of
an active substance in the
underground parts of the plant
has an inhibitory effect on the
root and shoot development of
cucumber, barley and tomato
plants. Tuber production in
Buckwheat [Fagopyrum es-
culentum] and Teff [Eragrostis
tef(E. Abyssinica)] was also
affected.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlverslty of Florlda/1989


C~









Jimson Weed

Datura stramonium L.
Solanaceae
Nightshade Family


Photograph: Arlyn W. Evans


Mature Plant
Jimson Weed is an annual, 0.5
to 1.5 cm tall. The stems are
smooth, green, hollow and
branching. The leaves alternate,
on stout leaf stalks, and are
large, ovate and 7 to 15 cm
long, with margins irregularly
cut and toothed. The flowers
are white and solitary on short
stalks, in the forks of the
branches; the corolla is trumpet
shaped, 7 to 10 cm long, 5 cm
wide at the mouth, 5-lobed;
and the stamens, 5 in number,
are attached to the tube slightly
below the middle. The fruit is a
spiny, ovoid, green, 4-celled
capsule about 5 cm long. The
fruit develops rapidly, splitting
open at the top when mature.
The seeds are many, dark
brown, wrinkled and pitted on
the surface.

History
The generic name "Datura" is
taken from the Arabic name for
this plant, "Dhatura." The Latin
species name "stramonium" is
the old generic name for this
genus. The word is thought to
be from strumaa" which means
swollen.


Habitat
This weed is found in cultivated
and disturbed areas throughout
the southeastern United States,
and throughout temperate and
tropical areas of the world.

Biology
Seeds from this weed re-
sponded to GA3 at a concentra-
tion of 10-2M with germination
of 36 percent, while Thiourea
at 10-3M increased the germi-
nation to 35 percent. Seeds
were found to germinate at a
rate of 12 percent when pre-
pared in a water-agar solution.
All parts of this plant are
poisonous.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlversity of Florida/1989


Photograph: Wayne L. Currey


Seedling
The cotyledons are narrow,
long 124 mm) and pointed. The
leaves are alternate, somewhat
heart shaped, especially at the
base, with smooth edges. The
stem and leaf petioles are
purplish In color.










Carolina

Geranium

Geranium carolinianum L.
Geraniaceae
Geranium Family


Photograph: John D. Tobe


Mature Plant History


Carolina Geranium is an annual.
much-branched plant forming a
circular growth pattern from
the center of the plant, and
may be ascending to erect (to
0.6 m tall from a tap root). The
leaves are up to 7 cm wide and
are suborbicular to kidney
shaped in outline, deeply di-
vided into 5 to 7 divisions and
lobed. This plant has leaves at
the base and on the stem,
which may be either oppositely
or alternately arranged and on
petioles of variable length. The
flowers usually occur in pairs
or in compact clusters. The 5
sepals are up to 7 mm long
with a 1 to 2 mm long tip
(mucro). The 5 petals range in
color from pale pink to pale
purple. Each flower usually
produces 5 seeds. The seeds
are enclosed in a 5-lobed cap-
sule with a 13 to 15 mm long
central "beak." On maturation,
the capsule springs open from
the base and the 5 divisions
curve upward elastically, fre-
quently dispersing the seeds
for considerable distances. The
seeds are about 2 mm long,
prominently veined in a rectan-
gular pattern, and oblong in
shape.


The genus name Geranium is
an old Greek name derived
from the word for crane. The
long beak of the fruit was
thought to resemble the beak
of that bird. The species name
carolinianum is a Latinized
English word which means of
Carolina, and refers to the
origin of the first named collec-
tion.

Habitat
This weed occurs in disturbed
areas, gardens, cultivated fields,
pastures, roadsides and waste
places throughout Florida, the
United States, southern British
Columbia and Ontario, the
West Indies and Mexico.

Biology
The seeds are eaten by birds
and rodents. The seeds are
reported to have astringent,
febrifuge, diuretic and nephritic
properties.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlverslty of Florlda/1989


Photograph: John D. Tobe
Seedling
The stems are brown to pink,
with a dense cover of short,
downwardly directed hairs. The
cotyledon blades are rounded
and broadly flattened at the
apex. The flattened tip Is slightly
Indented with the midvein
extended into the notch as a
small ridge. The upper surface Is
green while the lower surface Is
tinged pink, and both sides are
hairy. The leaves develop alter-
nately.


_~iiiXiiiiiiiii/iii:ii:ii:::::::::::::::









Hydrilla

Hydrilla verticillata (L.f.) Presl
Hydrocharitaceae
Frog's-bit Family


Photograph: Vernon V. Vandlver, Jr.

Mature Plant
Hydrilla is a submerged aquatic
perennial plant with ascending
stems which become horizontal
and heavily branched near the
water surface. Specialized veg-
etative buds are called turions.
They are formed somewhat
infrequently in the axils of the
leaves on the upper part of the
stem. Horizontal stems grow
into substrate to form subterra-
nean turions which are incor-
rectly called "tubers." The
narrow leaves are 1 to 2 cm
long, sessile and whorled in
groups of 4 to 8 but sometimes
may be opposite on the lower
stems. The blades have a row
of teeth along the margin and
on the underside of the leaf
along the midvein. The teeth
are deciduous and leave ele-
vated projections. The small
flowers are of one sex and
these are usually found on
separate plants. The female
flowers are composed of six,
translucent, colorless segments
and a colorless to purplish
floral tube. These are borne
from a green sneath. The male
flowers are borne on a snort
stalk and are free floating at
maturity.


History
Hydrilla is derived from the
Latin hydro plus ilia meaning
something that lives in the
water. Verticillata is the Latin
word for whorled, and refers to
the leaf arrangement of this
plant.

Habitat
This weed is found throughout
Florida in freshwaters mainly in
the southern and central re-
gions. It is also found in all of
the gulf states including Geor-
gia, and from Maryland to
California. It was introduced
from the Old World.

Biology
Hydrilla grows very rapidly
from rootstocks, subterranean
turions, vegetative buds (tur-
ions), and vegetative nodes.
Only one node (whorl of
leaves) is necessary for growth.
In clear water the plant can
grow in depths of more than
40 feet. When growing from
the bottom the leaves may be
up to, or more than, 6 inches
apart. The leaves on the lower
part of the stem may be oppo-
site. As the stem reaches the


Photograph: Kenneth A. Langeland
Seedling
A hypocotyle up to 6 mm long
Is developed from the seed. A
node on the hypocotyle near
the seed produces a short stem
1 to 4 mm long. The seed coat
sloughs off. At the first node on
the stem 3 leaves and a few
roots are produced. One to
several branches usually occur
at this same first node.
surface the leaves become
whorled and occur much more
closely together on the stem.
As the stem reaches the surface
extensive branching occurs,
often forming dense mats.
Hydrilla can spread rapidly and
will replace native vegetation.
Pollination occurs above the
surface of the water. The pollen
is dispersed aerially and must
land dry on the stigma.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlverslty of Florlda/1989


I CI'~''"""""`''









East Indian

Hygrophila
Hygrophila polysperma (Roxb.) T
Anderson
Acanthaceae
Acanthus Family


Photograph: Vernon V. Vandiver, Jr.

Mature Plant Habitat


East Indian Hygrophila is an
aquatic annual and is sparsely
hairy with both aquatic and
emergent stems. The aquatic
form has opposite, elliptic to
oblong leaves to 4 cm long.
The emergent form differs in
having smaller, narrower and
darker leaves. The flowers are
stalkless in the leaf axils of the
emergent stems and are sur-
rounded by 2 hairy modified
leaves 5 to 15 mm long. The
outer portion of the flower
(sepals) is green, hairy, and
divided nearly to the base. The
inner portion of the flower
(petals) is blue to white, hairy
and up to 9 mm long. The fruit
is a capsule to 9 mm long cov-
ered with hairs especially near
the top.
History
The Greek generic name Hy-
grophila means water-loving.
The Greek word polysperma
means with many seeds. First
collected in Florida in the mid-
1960s, East Indian Hygrophila
has reportedly been of sufficient
density to cause a problem
only during the past 4 years.


In Florida this weed is found in
scattered locations south of
Orlando. It is found also in wet
areas throughout India to an
altitude of 1600 m and in Indo-
Malaysia. It was introduced to
Florida from cultivation.

Biology
East Indian Hygrophila is
doubtlessly spread from its use
as an ornamental plant by the
aquarium plant industry. Plants
range in color from the light
green ofjuvenile specimens to
dark green mature plants fre-
quently with purple tips.
Rooted in the hydro-soil, dense
stands of shoots are produced
with elongated nodes and
large leaves which will extend
upward to the water surface
from depths exceeding 3 m.
Emergent shoots have smaller,
more compact, darker green
leaves and shorter internodes.
When rooted on moist banks
the shoots are only 15 to 20
cm tall. If submersed the emer-
gent shoots will drop their
leaves and produce new leaves
of the underwater type.


Photograph: Vernon V. Vandlver, Jr.

Seedling
No seedlings have been seen.









Elongation of shoots begins
with the increase in water
temperature around March.
Shoots reach the surface in late
spring. During the summer,
fragments with numerous ad-
ventituous roots break away
from the mats. Upon contact
with soil they will readily root.
During the hot weather of late
August the whole shoot will


break off near the root crown.
These shoots form large, heavy,
floating mats which can cause
severe water flow problems.
The whole mat can sink and
produce a new colony, or indi-
vidual pieces can do so. The
old root crowns quickly pro-
duce new shoots which grow
slowly during the winter.


Hygrophila is difficult to control
with available herbicides. It is
much more difficult to control
than Hydrilla and requires
higher rates of herbicides. In
mixed stands of Hydrilla and
Hygrophila, herbicide treat-
ments to control Hydrilla will
select for Hygrophila.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlversity of Florida/1989









Scarlet

Morning-

glory
Ipomoea hederifolia L.
Convolvulaceae
Morning-glory Family


Photograph: Ted J. Stelter


Mature Plant
Scarlet Morning-glory is a twin-
ing, smooth to hairy annual
vine. The leaf shape is extremely
variable. The leaves are gener-
ally ovate in shape with pointed
tips and heart-shaped bases
and are commonly deeply
3-lobed. The flower stalks are
usually as long as, or longer
than, the subtending leaf. Each
flowerstalk may bear a simple
flower or may have several
flowers. The sepals (outer layer
of the flower) are oblong and
1.5 to 3 mm long, excluding
the sharp pointed tip. The tip
may be as long as, or longer
than, the broader portion
below. The joined petals may
be scarlet to yellowish to
orange-red and from 2.5 to 4.5
cm in length. The fruit is a
round capsule up to 8 mm in
diameter containing a few
seeds.
History
Ipomoea is derived from the
Greek words ips and homoios
meaning worm-like, referring
to the vining habit. The Latin
word hederifolia means having
leaves like Ivy.


Habitat
This plant occurs in moist ham-
mocks, thickets and disturbed
sites throughout Florida. It may
extend into southern Georiga,
westward to Texas and Mexico,
and occurs in the West Indies.
Through cultivation it occurs
throughout the tropics.
Biology
The root is used medicinally
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlverslty of Florida/1989


Photograph: Ted J. Stelter
Seedling
The cotyledons are thickly U-
shaped with lobes one half the
length. They are on long stalks.
The veins are visible on the
upper surface.










Pitted

Morning-

glory
Ipomoea lacunosa L.
Convolvulaceae
Morning-glory Family


Photograph: Ted J. Stelter

Mature Plant
Pitted Morning-glory is a
sparsely hairy, twining annual
with a slender tap root. The
leaves are ovate with a pointed
tip, and may be up to 9.4 cm
long and 8.0 cm wide. The leaf
margin is usually purple and
may be smooth or deeply 3-
lobed. The flower stalks are
rough and bear 1 to 3 flowers.
The sepals (outer layer) are
somewhat leathery in texture
and up to 11.5 mm long with a
fringe of hairs along the margin.
The petals arejoined, white to
purplish, and may be up to 2.5
cm long. The anthers are purple;
the stamens and the stigma are
shorter than the petals. The
fruit is a rounded or slightly
flattened, hairy capsule up to
10 mm broad.

History
Ipomoea is derived from the
Greek words ips and homoios
meaning worm-like, referring
to the vining habit. The Latin
word lacunosa means air-spaces
and refers to the venation of
the leaves.


Habitat
Pitted Morning-glory occurs in
cultivated fields, meadows,
roadsides and waste areas
throughout most of the eastern
United States, in northern
Florida (Jackson County), and
sporadically in southern Florida
in Dade and Palm Beach Coun-
ties.

Biology
I. lacunosa will cross with .
trichocarpa. Sample measure-
ments have shown a vine
weight of 443.6 to 620.3 g.
Seeds number 5,928 to 13,736
seeds per plant and weigh 21.2
to 22.1 mg per seed. Germina-
tion increased as temperature
increased from 16 to 320C over
a period of 4 days. Maximum
germination occurred after the
second day at 320C. This species
is sensitive to moisture stress;
after 6 days at 10 bars, germina-
tion was only 35.2 percent,
while seeds exposed to 0 os-
motic pressure reached a peak
of 99 percent germination after
the third day. Seeds (a small
percentage) have germinated
after being stored 39 years.
Seed longevity decreased from


Photograph: Ted J. Stelter
Seedling
The cotyledons are broad
and flattened at the base
with a deep notch.


100 percent germination to 13
percent germination after 5.5
years at three depths (8, 23
and 38 cm). This plant is not
shade tolerant. The presence of
wheat has produced a much
reduced rate of growth.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlversty of Florida/1989









Cypress-vine

Morning-

glory
Ipomoea quamoclit L.
Convolvulaceae
Morning-glory Family


Photograph: Ted J. Stelter
Mature Plant
Cypress-vine Morning-glory is
an annual, smooth, twining
vine. The leaves are ovate in
general outline but deeply
divided into many linear seg-
ments or lobes. Each segment
is about I mm or less in width.
The entire leaf may be up to
7.5 cm long and 4.5 cm wide.
The flower stalks may be short-
er than, or about as long as,
the leaf blade underneath.
Each flower stalk bears from 1
to 3 flowers on stalks which
may be up to 2.5 cm long. The
individual flower stalks are
gradually enlarged from the
base toward the flower. The
sepals (outer layer) are from 5
to 7 mm long and oblong
shaped. They have a short,
sharp, flexible point at the apex
and overlap. The joined petals
are usually crimson or occasion-
ally may be white. They may be
from 2.7 to 4 cm long and
about 2 cm broad at the top.
The stamens and the stigma
are slightly longer than the
flower tube. The fruit is a
round-ovoid capsule, 5 to 8
mm long, usually containing
four seeds.


History
Ipomoea is derived from the
Greek words ips and homoios
meaning worm-like, referring
to the vining habit. The Greek
word quamoclit means dwarf
kidney bean which could refer
to the shape of the cotyledons.
Habitat
This plant occurs throughout
Florida, westward to Texas,
northward to Kansas, eastward
to Virginia and throughout the
tropics. It is commonly found in
cultivated fields, roadsides and
waste areas within this range.
Biology
Germination increased as tem-
perature increased from 16 to
320C over a period of four
days. Maximum germination
was obtained between 24 and
320C after four days. Osmotic
pressure of 10 bars during a
4-day period limited the germi-
nation to 4 percent while at 0
bars germination was 99.8
percent. Sample measurements
have shown a vine weight of
290.0 to 607.8 g, a seed count
of 8640 to 9596, and a seed
weight of 13.3 to 13.5 mg.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlverslty of Florida/1989


Photograph: Michael Riffle
Seedling
The cotyledons are about 5 to 6
cm long and up to 3 mm wide.
Each cotyledon consists of two
widely divergent, somewhat
linear, tapering lobes. The first
leaves are deeply divided with
many linear segments.









Sharp-pod

Morning-

glory
Ipomoea trichocarpa Ell.
Convolvulaceae
Morning-glory Family


Photograph: George Davis

Mature Plant History


Sharp-pod Morning-glory is a
sparsely hairy perennial which
flowers the first year. The leaves
are heart shaped with a sharp
tip. The leaf margin may be
smooth, 3-lobed or occasionally
5-lobed. The leaf size is usually
less than 9 cm long and 7 cm
wide, although some specimens
may be up to 10.5 cm long and
8.8 cm wide. The flower stalks
commonly bear from I to 5
flowers (rarely up to 10). The
non-hairy stalks are rough
textured due to the presence of
short, broad growths or pro-
tuberances. The sepals (outer
layer of the flower) are some-
what leathery, oblong-elliptic
in shape and have a sharp tip.
They may be as long as 15 mm
and range from smooth to
hairy at the base, but usually
have fine hairs along the mar-
gins. The joined petals range
from pink to purple (rarely
white) in color, and are up to
4.5 cm long and about as
broad. The stigma and stamens
are shorter than the flower
tube. The fruit is a hairy, spheri-
cal capsule up to 9 mm broad.


Ipomoea is derived from the
Greek words ips and homoios
meaning worm-like, referring to
the vining habitat. Trichocarpa
is from the Greek words tricho,
hair, and carpo, fruit.
Habitat
I. trichocarpa is native to the
southeastern United States and
occurs throughout Florida
westward into Mexico and
northward to southern North
Carolina. Within this range it is
usually found in thickets, fields,
roadsides and disturbed areas.

Biology
/. trichocarpa has hybridized
with I. lacunosa to such an
extent that very few if any
pure populations of /.
trichocarpa exist. Sample mea-
surements have shown a vine
weight of 279.7 g when mature
seeds were collected, a seed
weight average of 19.1 mg per
seed, and 8,824 seeds were
collected from a single plant.
(Note: These measurements
fluctuate from year to year.)
Germination increased as tem-
perature increased from 16 to
320C over a 4-day measurement


Photograph: Walter S. Judd
Seedling
The cotyledons are broad and
flattened at the base with a
deep notch. The lobes of the
cotyledons extend 2/3 to 3/4 of
the total length. The veins are
visible on the upper surface.


period. (Germination was high-
est at 320C.) An osmotic pres-
sure (used to test moisture
stress) of 10 bars limited the
germination to 58 percent
while at 0 bars germination
rose to 86 percent. These values
were measured after a 6-day
period.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlversity of Florlda/1989









Small-flower

Morning-

glory
Jacquemontia tamnifolia (L.)
Griseb.
Convolvulaceae
Morning-glory Family


Photograph: Wayne L. Currey

Mature Plant Habitat


Small-flower Morning-glory is
an herbaceous annual with
hairy, twining stems that can
grow up to 2 m in length. The
leaves are ovate to elliptic-ovate
with pointed ends. The leaf is
from 2.3 to 12.2 cm long and
from 0.8 to 9.7 cm wide. The
petioles are from 2 to 8 cm
long. The flowers are produced
on long stalks in leafy heads.
The flowers are bell shaped
and measure 12 to 16 mm long
and 1.5 to 3 cm broad. There
are 5 stamens and 2 flattened
stigmas. The capsule are 4-
seeded and 4 to 6 mm broad.
The seeds are brownish black
and are approximately 2 mm
long.
History
This genus is closely related to
Ipomoea. The generic name
Jacquemontia commemorates a
French botanical explorer, Victor
Jacquemont. The species name
tamnifolia is from Tamus, a
genus of plants and the Latin
folia, leaf. It means that the
leaves resemble those of Tamus.


This weed is a native of tropical
America and is found in culti-
vated fields and other disturbed
ground in the southeastern
United States and from the
West Indies to Brazil.
Biology
Seed germination ranged from
0 to 22 percent over a 4-day
period at 160C. An increase in
temperature to 320C increased
germination from 61.8 to 69.2
percent over a 4-day period.
Germination at 0 bars increased
from 85.8 to 93.8 percent over
a 2-day period; however, a
continual decrease in germina-
tion occurred from 0 to 10
bars. At 10 bars after the sixth
day, germination was only 1.5
percent.
A single plant weighed 282
grams at the time of mature
seed harvest. The number of
seeds produced on this plant
was 11,028 while the average
weight per seed was 5.3 g.
Scarification for 25 to 60 sec-
onds produced a germination
greater than 80 percent after
seven days. Seed depth affected
germination. Seeds had a 30


Photograph: Wayne L. Currey
Seedling
The stems are green, and the
cotyledons are heart shaped,
about 1 cm long, and light
green with the major veins
appearing as depressions in the
upper surface.


percent germination rate at the
surface, 25 percent when
planted 0.5 cm deep, and 65
percent when planted at a
depth of I cm. No emergence
was recorded when planted 4
cm or greater.
-David W. Hall and Vernon V Vandiver, Jr.
IFAS/Unlverslty of Florida/1989









Limnophila

Umnophila sessiliflora (Vahl)
Blume
Scrophulariaceae
Rgwort Family


Photogr: Vrnon V. Vndivr, Jr.

Mature Plant
Lmnophila is an aquatic, or
nearly aquatic, perennial herb
with two kinds of whorled
leaves. The submerged stems
are smooth and have leaves to
30 mm long which are re-
peatedly dissected. These differ
from the emergent stems which
are covered with flat shiny
hairs and have leaves up to 3
cm long with toothed margins.
The emergent stems are usually
2 to 15 cm above the surface
of the water. The flowers are
stalkless and borne in the leaf
axis. The lower portion (sepals)
have 5, green, hairy lobes, each
4 to 5 mm long. The upper
portion is purple and composed
of 5 fused petals forming a
tube with 2 lips. The lips have
distinct purple lines on the
undersides. The fruit is a capsule
containing up to 150 seeds.

History
Limnophila is derived from a
Latin word which means pond-
loving and refers to its aquatic
existence. Sessiliflora, also Latin,
means sessile-flowered and
refers to this plant's stalkless
flowers.


Habitat
This weed is found in or near
organically stained, acidic or
clear, slightly alkaline water
sporadically throughout Florida.
It is also naturalized in south-
western Georgia and Texas. It
was introduced from the Old
World.

Biology
Limnophila can grow in water
up to 3 meters deep. Reproduc-
tion is by fragmentation of the
stem or by seeds. Only a small
portion of the stem is necessary
for growth to occur. In late fall
the mats of Limnophila break
loose from the hydro-soil. Since
the fruit is mature in the late
fall the floating mats spread
the seeds as they move. A toxin
present in the stem tissue may
prevent herbivorous fish from
eating the plant. It tolerates
low temperatures.
--D fAvld HSll and Vy f nd1I, J
IF.Stlnlveslt of Floida/1"98


Phmotopraph: Vrnon V. Vndlwm Jr.
Seedling
Seedlings of Umnophlla are
reported as Infestations along
the shoreline.









Black Medic

Medicago lupulina L.
Leguminosae (Fabaceae)
Bean Family


Photog : r .yne L Cu ey

Mature Plant History


Black Medic is an annual, 10 to
40 cm long, with trailing stems
that are short-hairy to smooth.
The leaves have 3 leaflets. The
leaflets are almost circular to
elliptic, mostly I to 2 cm long,
3 to 10 mm wide, hairy and
toothed. The stipules are lan-
ceolate to ovate-lanceolate,
usually 5 to 10 mm long, with
smooth or slightly toothed
margins. The flower heads are
rounded to slightly elongated
with 10 to 50 flowers. The
flower stalks are 0.5 to 4 cm
long, and are hairy or smooth.
The calyx (outermost flower
part) is short-hairy with a tube
0.5 mm long, and lobes 0.6 to
1 mm long. The petals are
yellow. The fruit is a kidney-
shaped spineless pod that is
reticulate, I -seeded, 2 to 3 mm
in diameter, hairy or occasion-
ally with spreading glandular
hairs and nearly black at matur-
ity. Each pod contains one gold
or brown seed from I to 2 mm
long.


Medicago is derived from the
Greek word medice. Medice is
the Greek name of Alfalfa
which is in this genus. The
Latin word lupulina means
hop-like, referring to the flower
heads

Habitat
M. lupulina can be found in
waste areas, turf and roadsides
throughout the southeastern
United States and northward
to Canada. It was introduced
from Europe.

Biology
Black Medic is used for green
fodder, green manure and hay.
The seeds have some value for
birds and rodents.
-DMd Hl and Vernon V. Vndlf Jr
IrMWUnhWmft of Flid1l9(9


Ptogrph: John D. Tobe
Seedling
The cotyledons are 4 to 9 mm
long, dull green and pale be-
neath. The leaves have a few
short hairs. The first leaf Is sim-
ple; all other leaves are
trlfollate. The leaf stalk Is hairy
with stlpules at Its base.









Catclaw

Mimosa

(Giant Sensitive Plant)
Mimosa pigra L.
Leguminosae (Fabaceae)
Bean Family


Photograph: Deborah White


Mature Plant
Catclaw Mimosa is a much-
branched, hairy, perennial shrub
typcially I to 4 m tall. The
alternate leaves are twice com-
pound with 6 to 12 paired
branches pinnaee) each contain-
ing 15 to 25 pairs of leaflets.
The stems, branches and leaves
contain prickles or thorns which
are slightly bent downwards.
The flowers are in heads
(puffballs) about I cm wide,
with numerous pink stamens
extending outwards. The fruits
are flattened, hairy, and the
pods are arranged in clusters.
Individual 1-seeded sections of
the pod break out at maturity
leaving the upper and lower
margins intact like a frame. The
seeds are gray-brown, about 6
mm long and 3 mm wide.

History
Mimosa is derived from the
Greek and refers to the sensi-
tive leaves of this and some of
the other species in the genus.
Pigra, a Latin word, means
slow and pertains to the move-
ment of the leaves.


Habitat


This weed is found in disturbed
and waste areas near water,
and is widely scattered from
Highlands County in central
Florida southward. Native in
the American Tropics, this weed
now extends throughout the
tropics of the world.

Biology
This species is able to colonize
new areas rapidly because of
its complex morphological and
physiological characteristics. It
was first introduced into South-
east Asia as a cover crop and
for erosion control in Thailand
in 1947. It is now widely distri-
buted in Asia. Seeds are often
produced year round in the
tropics and a mature plant may
produce 42,000 or more seeds
a year. The seeds remain viable
for many years and may germi-
nate in a wide range of environ-
mental conditions. Once estab-
lished, this plant can withstand
almost total submergence by
readily forming adventitious
roots from aerial and sub-
merged stems. It can tolerate
upland soils and moisture re-
gimes such as occur along


Photograph: Dan Tyer
Seedling
The cotyledons are oblong,
about 1 cm long, thick, and
blunt at the tip. The stem has a
few scattered appressed
halrs.The first true leaf Is once
compound. The next few leaves
are twice compound or divided.
The next few leaves are twice
compound or divided with two
pinnae. Above this the next leaf
or two have 4 plnnae. Then the
normal adult leaves are pro-
duced.









roadways, in secondary forests,
and even in highly saline marine
habitats. Along water courses
thickets may block access,
restrict water flow and increase
levels of sedimentation and
nutrients.
Germinating seeds and seed-
lings can be killed by water
inundation. Germination is
induced by ground fires or
other processes that can crack
the hard outer coat of the
seeds. After fires the seedling
has an advantage in the nutri-


ent-rich exposed areas. This
weed is frequently found in
disturbed areas. Since these
areas are increasing it is likely
the Catclaw Mimosa will in-
crease also. Extensive estab-
lished populations probably
can not be eradicated. Cutting
and burning or mechanical
operations can control the
spread of this plant, but rapid
regrowth reduces the effective-
ness. Repeated treatments are
necessary for chemical control.
Biological control such as plant
pathogens and insects are


currently being researched.
Management will most likely
involve all of these efforts. The
extensive open wetlands and
waterways in Florida are similar
to the habitats Mimosa pigra
has invaded elsewhere. The
biological potential of this
weed makes it imperative that
all populations be reported.
Source of biological treatment: in part,
Deborah White. 1985. Weed Alert -
Mimosa pigra. Center for Aquatic
Weeds, University of Florida.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlverslty of Florida/1989









Balsam-apple
Momordica charantia L.
Cucurbitaceae
Cucumber Family


Photograph: Wayn L Curry


Mature Plant
Balsam-apple is an annual and
has a creeping or climbing
stem. The alternate leaves have
petioles 3 to 6 cm long, and
thin blades. The leaf blades are
hairy to smooth, deeply pal-
mately 5- to 7-lobed and up to
12 cm wide. The lobes of the
blades are rounded to pointed
and usually have teeth on the
margins. The flowers usually
occur singly on stalks bearing a
modified leaf near the middle.
The sepals (outermost flower
parts) are oval and to 4.5 mm
long. The yellow petals are
rounded or indented at the tips
and up to 1 cm long. The fruit
is broadly egg shaped, beaked,
bumpy, ribbed, to 10 cm long
and golden yellow to bright
orange. At maturity the fruit
breaks, bursting open along
the 3 valves. The orange pulp
contains bright red arils which
enclose the seeds. The seeds
are elliptic, flat, and 9-12 mm
long.


History
Momordica is a Latin word that
means to bite and refers to the
look of the uneven seeds. The
species name charantia is un-
clear as to meaning but could
be Latin and refer to the
pointed fruit

Habitat
This weed is found in ham-
mocks, disturbed sites, turfs
and ornamental landscapes
and citrus groves from Florida
to Texas on the coastal plain, in
the West Indies, Tropical
America and Old World Tropics.

Biology
The ripe fruits and seeds are
toxic.
-Dvid W. Hall and Vfnon V. Vandte. Jr.
IFS/Unlwnlty of Florlda/1989


Photograph: Ted J. Sttner
Seedling
The stem Is ridged and has small
hairs. The first leaves are un-
lobed with broad teeth along
the margins and have a heart-
shaped base.









Creeping

Wood Sorrel
Oxalis comiculata L


Southern

Yellow Wood

Sorrel
Oxalis florida Salisb.
Oxalidaceae
Wood Sorrel Family


Photograph: wayn L Currey

Mature Plant Habitat


These Wood Sorrels can be
annual or perennial tap rooted
herbs, bushy or mat forming,
and 0.1 to 0.5 m tall. Branching
from the base and often rooted
at the nodes, the upper portion
is ascending or weakly erect,
smooth or hairy. The leaves are
arranged alternately along the
stems. A single long stalk arises
from the axils of the leaf, from
which extend 3 flower stalks,
each with a single flower. The
flowers are 7-11 mm wide and
have 5 yellow petals. The fruit
is a capsule, 1 to 1.5 cm long,
cylindric, pointed apically, and
5-ridged in cross section. The
seeds are oval in outline, api-
cally rounded, basally pointed,
flattened in cross section, light
brown, and have a surface
distinctly transversely ridged.

History
The genus name Oxalis is a
Greek word meaning sour.
Sour refers to the acidic taste
of the foliage. The Latin species
name corniculata means horned
and refers to the look of the
fruits. The Latin species name
florida means flowering.


These weeds are found
throughout Florida. They are
common in the southeastern
United States; from Newfound-
land to North Dakota; and
southward to Mexico. O. cor-
niculata is a cosmopolitan weed
occurring in the Old World and
in temperate and tropical re-
gions of North, Central and
South America and the West
Indies.
Biology
The foliage contains oxalic acid.
-Dvld W. HIll and Vrn V. Vndher, Jr.
IrASUnvwnlty of Forlda/1989


Photograph: John Tobe
Seedling
The stem Is short and pink-
brown. The cotyledon blades
are often tinged pink on the
lower surface and Joined near
the base. The trifollate leaves
are alternate, with thin, heart-
shaped, leaflet blades having a
distinct apical Indention. The
blades are smooth on the upper
surface, slightly folded upward
lengthwise along the major
vein, and have a few appressed
hairs along the veins on the
lower surface and along the
lower portion of the margins.










Maypop
(Passion-flower)

Passiflora incarnata L.
Passifloraceae
Passion-flower Family


Photogrph: Wayne L Curey

Mature Plant Habitat


Maypop Passion-flower is a
perennial. The stems are smooth
or have small hairs. The growth
pattern is erect, creeping or
climbing. The leaf blades are
palmately 3-lobed (rarely 5-
lobed) and 6 to 15 cm long.
The leaves have leaf-like stipules
and conspicuous glands on the
petioles. The flowers are axillary
and solitary. The flower stalks
are 5 to 10 cm long and termi-
nate with a whorl of 3-toothed
modified leaves, 3 to 6 mm
long. The 5 sepals are usually
green, or sometimes light laven-
der to white. The sepals are 2.5
to 3.5 cm long. The 5 petals are
bluish white and 3 to 4 cm
long. The fruit is a green, fleshy,
egg-shaped berry, turning
yellowish green. The seeds are
dark brown and 4 to 6 mm
long.

History
Passiflora is derived from Latin
and means passion and flower.
The Latin species name incar-
nata means flesh colored and
alludes to part of the flower.


This weed is found throughout
Florida on dry soils, especially
along roadsides and in citrus
groves and old fields. Its native
range extends westward to
Texas, eastward to Virginia and
northward to Missouri. It was
introduced further north from
its previous southern range. It
is also found in Bermuda.

Biology
Reproduction is by seeds and
root shoots. Cultivation may
break apart and move root
shoots to new areas. The edible
fruit is called a Maypop.
-DNavd W. Hall and rnon V. Vandler, Jr.
IFS/Univerlty of Floldan/MS


Phtoogph:Va wayMn Currey
Seedling
The stem Is smooth. The first
leaves while sometimes not as
lobed as the later leaves have
two characteristic glands at the
base of the blade on the petiole.









Cutleaf

Ground-

cherry

Physalis angulata L
Solanaceae
Nightshade Family


Photograph: Wyn L Currey


Mature Plant
Cutleaf Ground-cherry is an
annual herb growing to 1
meter in height. It is usually
hairless; however, occasional
plants have short appressed
hairs especially on the younger
parts. The leaves are ovate to
lanceolate, 4 to 10 cm long
and 3 to 6 cm wide. The
petioles are up to 4 cm long or
longer. The leaf margin is usu-
ally irregularly toothed but may
be smooth. The leaf bases are
unequal. The flowers are borne
on stalks from 5 to 40 mm in
length. The corolla is yellow,
usually without spots or occa-
sionally with distinct spots, and
is from 4 to 12 mm long and 6
to 12 mm wide. The anthers
are bluish or violet, up to 2.5
mm long and are borne on
stalks up to 5 mm long. The
green outer layer is 4 to 7 mm
long with triangular lobes
about as long as the tube. The
fruit is enclosed in the outer
layer. This outer layer (calyx)
grows around and encloses the
fruit and becomes 10-angled or
ribbed, 20 to 35 mm long and
from 15 to 25 mm wide; it is
borne on a stalk 1 to 4 cm
long.


History
The genus name Physalis, a
Greek word, means bladder
and refers to the inflated calyx,
while the Latin species name
angulata means angled and
refers to the stems.
Habitat
This weed occurs in fields,
pastures, roadsides and open
woodlands throughout Florida
to eastern Texas and northward
to Pennsylvania. It prefers dis-
turbed sites.

Biology
Maximum germination occurred
at 210 C with 10 hours of alter-
nating temperatures and 300 C
with 14 hours of alternating
temperatures. Planting depth
directly affected emergence
with a decrease from 89 per-
cent to 0 percent with a corre-
sponding increase of depth
from 0.0 cm to 10.0 cm.
-David W. Hall and V rnon V. Vndver, Jr.
IFAS/UnierOlty of Florida/1989


Photograph: John 0. Tobe
Seedling
The cotyledons are ovate with
reddish petioles and without a
distinct mldveln. The first leaves
are similar In shape to the
cotyledons, but with an acute
apex and evident venation.










Wild Radish

Raphanus raphanistrum L.
Cruciferae (Brassicaceae)
Mustard Family


Photogrph: John D. Tobe

Mature Plant
Wild Radish is a winter annual
or annual rising from a tap
root. This herbaceous plant can
reach 1 m in height The stems
of younger plants have stiff,
prickly hairs. The stems become
smooth with age. Branching
varies from one to several. The
hairy leaves are lyre-like
(broader at the tip than at the
base) with rounded, deeply,
irregularly cut lobes. This lobing
covers about two-thirds of the
blade from the base upwards.
Hairs occur on both surfaces.
The flowers are yellow to white
with purple veins in the petals.
All the parts of the flower are
in fours. The seed pod is nar-
row, 2 to 6 cm long, 3 to 5 mm
wide, and pointed at the tip.
The mature, brown pod is
jointed with few to several
segments. Each 1- or 2-seeded,
ribbed segment breaks cross-
wise from the adjoining seg-
ments. The longitudinal ribs are
apparent only at maturity The
seeds are 2 to 3 mm long and
have a thin, brown seed coat.
History
The descriptive Greek name of
the genus Raphanus means
quickly appearing and refers to


the rapid germination of these
plants. Raphanistrum from the
same Greek root is an old name
once used for this genus.

Habitat
This weed is a native of north-
ern Europe and northern Asia
and is found in disturbed areas
and cultivated fields over most
of the world.

Biology
This plant germinates readily It
is a winter annual, dying at the
onset of hot weather, but some
plants live for one entire year
in Florida.

Separation from Wild
Mustard
Wild Radish is often confused
with Wild Mustard (Brassica
kaber). Wild Mustard does not
occur as a weed in crops in
Florida. The veins in the upper
surface of Wild Mustard cotyle-
dons are not apparent in com-
parison to the impressed veins
of Wild Radish cotyledons.
Mature plants of Wild Mustard
only have yellow flowers while
flowers of Wild Radish can be
yellow, white and rarely laven-
der. The only sure distinction
between mature plants is in


rnoograpn: MI.laI Rm
Seedling
The seedlings have kidney-
shaped cotyledons with evident
veins somewhat Impressed into
the upper surface. The first
leaves have smooth margins
when they emerge, but these
become lobed with age. The
first leaves are also quite hairy.


the fruits. The fruits of Wild
Mustard do not have crosswalls
between the segments and
they split longitudinally. The
fruits of Wild Radish contain
crosswalls between the seg-
ments and do not split. The
segments of Wild Radish decom-
pose with age, releasing the
seeds.
-David W. Hall a VenonV. V.ndlv r,Jr.
IFAS/Unlvnlty of FlorIld1989










Brazil Pusley

Richardia brasiliensis (Moq.)
Gomez
Rubiaceae
Madder Family


Pnolograpn DNmfa m Hil

Mature Plant
Brazil Pusiey is an annual or
perennial from a thickened
rootstock mnat may be deep Its
stems are up to 0 4 m long and
may be found growing pros-
:rate or ascending The stems
are freely brancnea, covered
witn somewhat stiff nairs and
rarely root from lower nodes
Tne leaves are opposite. elliptic
to ovate in shape and have a
pointed to rounded tip. The
leaf base is elongated and the
petiole may be almost absent
to 1 cm long. The leaves may
be up to 6.5 cm long and 2.4
cm wide and are rough tex-
tured on both sides. The
petioles of opposite leaves are
connected by stipules which
have become sheath-like. These
sheaths have ascending hairs
or bristles to about 5 mm long.
The flowers are in a terminal
head-like cluster, up to 15 mm
in diameter, of 20 or more
flowers. The flowers have typi-
cally 2 pairs of short, broad
leaves underneath. The upper-
most pair is usually much small-
er and at right angles to the
lower pair. The outer part of
the flower consists typically of
6 narrow lobes, up to 3.5 mm


long. which have hairy margins
Tne loDes are joined at me
base. forming a tude up to I 5
mm long The petals are also
united and are wnvre in colora-
tion The tube is funnelform in
shape and from 3 to 8 mm
long Each flower usually pro-
duces 3 nutlets up to 3 mm
long and 2 mm wide Tne out-
side of Ene nurlet nas snort
nick nairs

History
Richardia was named for an
English physician, Richard
Richardson. Brasiliensis refers to
the country of origin, Brazil.

Habitat
In Florida this plant occurs
throughout the state on dis-
turbed sites and roadsides, and
in pastures and lawns. It is
distributed in the southeastern
United States, from southern
Texas along the coastal plain to
southeastern Virginia.


Photograph: John D. Tobe
Seedling
The cotyledons are oblong and
smooth, with a distinct maroon
area near the base. The first
leaves are creased In the center,
covered with stiff hairs and at
right angles to the cotyledons.


Biology
This weed will bloom in almost
any month that lacks frost. The
thick fleshy root is considered a
reservoir for nematodes. This
species is frequently mixed
with Florida Pusley, Richardia
sabra.
-DaidW Hall .nd Vrnon V ndlvwr, Jr.
IFAS/U.niity of Florida/1989










Florida

Pusley

Richardia scabra L.
Rubiaceae
Madder Family


Photogaph: W1illiam loml.ey

Mature Plant
Richardia scabra is an erect to
prostrate, loosely branched
annual. The stems are hairy, up
to 0.8 m long and do not usu-
ally root at the nodes. The
leaves are oppositely arranged,
ovate to elliptic-lanceolate
shaped, up to 6.5 cm long and
2.5 cm wide. The leaves may
be almost smooth, except for
the margins, to rough on both
leaf surfaces, and predominantly
rough on principle veins. The
leaf apex may be rounded to
pointed. The leaf base is tapered
with petioles ranging from very
short to about 5 mm long. The
opposite leaves are connected
by a sheath with several as-
cending, hair-like appendages
from 2 to 5 mm in length.
The flowers are in a terminal
head-like cluster composed of
20 or more flowers. The head is
usually subtended by 2 pairs of
leaves. The second or upper
pair is usually much smaller
than, and at right angles to,
the lower pair of leaves. The
outer part of the flower consists
of 6 narrow lobes. These lobes
are joined at the base forming
a tube. The petals are also
united and are usually white to
occasionally pink or lavender


and funnelform in shape. The
tube ranges in length from 2 to
8 mm and the lobes of the
petals are from 0.5 to 2.5 mm
long.
Each flower typically produces
3 nutlets from 2 to 3.5 mm in
length and about 1.5 to 2 mm
in width. The nutlets are more
or less oblong to obovate
shaped. The outer surface of
the nutlet is covered with wart-
like protuberances.

History
Richardia was named for an
English physician, Richard
Richardson. The Latin word
scabra means rough and refers
to the texture of the plant.

Habitat
Richardia scabra is commonly
found in sandy savannas and
grasslands, on roadsides, turf
and in cultivated fields and
waste areas from central Florida
northward to southern Virginia,
and westward to Texas. Its
range is continuous from this
area southward through Mexico
and Central America to Colom-
bia, Ecuador, Peru and Bolivia
in South America, and Cuba
and Jamaica in the West Indies.
Specimens collected in other


Photograph: John D. TOM
Seedling
The cotyledons are oval and
smooth with a blunt, rounded
tp and a distinct maroon area
near the base. The first leaves
are creased in the center,
covered with stiff hairs and at
right angles to the cotyledons.


areas (Indiana in the United
States, and Rhodesia, Tanzania
and Transvaal in Africa) are
presumed to be adventive.

Biology
This weed will bloom in almost
any month that lacks frost It is
frequently mixed with Brazil
Pusley, Richardia brasiliensis.
-David W. H.ll and Vernon V. Vandiwe, Jr.
IMS/Unlvnery of Florlda/1989










Curly Dock
Rumex crispus L.
Polygonaceae
Buckwheat Family


Mature Plant
Curly dock is a stout perennial
with a tap root. These plants
can become 1.6 m high and are
relatively unbranched below
the flowers. The leaf margins
are curled and wavy The basal
leaves are 5 to 36 cm long and
2 to 12 cm wide. The flowering
portion at the top of the plant
has many dense flower clusters.
There are six green sepals (three
large and three small). The
flower stalk is at least as long
as, or up to 1.5 times longer
than, the larger sepals. There
are no petals. As the flowers
mature the innermost sepals
develop into three papery
wings, each with a swelling or
growth. One of the three
growths is larger than the
other two. The 3 sepals which
are approximately 3.5 to 6 mm
long enclose a small dry 3-sided
fruit.

History
The genus name Rumex is the
Latin name which was used for
this plant The Latin species
name crispus means curled and
refers to the leaf margins.


Photorph: John D. Tobe

Habitat
This weed is usually found on
seasonally moist ground
throughout the United States
and Canada. It is a native of
Eurasia.

Biology
Light and/or alternating temper-
atures are required for optimal
germination. Ethylene gas has
been found to increase germina-
tion in the light, but not in the
dark. Exogenous gibberellin,
GA3 and AC-94377 (a substi-
tuted phthalimide) promote
germination of the seeds in the
dark.
-David W. Hall and Wrnon V. Vlndlmv Jr.
IFAS/Unlvrilty of Florldl/1989


Photograph: John 0. Toll
Seedling
The cotyledon blades are ob-
long, tapering to the base, dull
green and slightly fleshy. The
mldvein is Indistinct as a slight
depression In the basal portion
of the upper surface. The leaves
are alternate, wavy on the
margins and covered with a
distinct glandular coating. The
petioles are flat and Joined at
the base Into a tube-like, white
to brown, papery sheath.









Heartwing

Sorrel
Rumex hastatulus Baldwin ex Ell.
Polygonaceae
Buckwheat Family


Photograph: George Davw


Mature Plant
Heartwing Sorrel is a winter
annual or rarely a short-lived
perennial. The leaves have the
shape of an arrowhead. The
male and female flowers are on
separate plants and are pink to
purple-red. The female flowers
have outer sepals 0.5 to 1.0
mm long. The fruit is 3 to 4 mm
long and has papery wings.
The wings are smooth. The
nutlets are about I mm long.

History
The genus name Rumex is the
Latin name which was used for
this plant. The Latin species
name hastatulus means spear
shaped and refers to the shape
of the leaves.

Habitat
This weed is common on sandy
soil throughout the coastal
plain of the southeastern
United States. It occurs in
Florida from the central part of
the state northward into the
southeastern United States to
Texas, and northward through
the Midwest to Montana and
Illinois and through the North-
east to Massachusetts.


Biology
The seeds are a common wild
bird food. Oxalates in this plant
can be poisonous. Thejuice
can cause dermatitis in sensitive
individuals.
-David W. Hall and VWnon V. Vandlvr. Jr.
IFAS/Unlrslty of PFlortfd1989


Photograph: Jonn D. TOe

Seedling
The cotyledon blades are thick-
ened and about 0.5 cm long.
The veins are not apparent. The
petioles are flat on the upper
surface. The first true leaves are
alternate.









Brazilian

Pepper-tree
Schinus terebinthifolius Raddi
Anacardiaceae
Sumac Family


Mature Plant
Brazilian Pepper-tree is a shrub
or small tree to 10 m tall with a
short trunk usually hidden in a
dense head of contorted, in-
tertwining branches. The leaves
have a reddish, sometimes
winged midrib, and have 3 to
13 sessile, oblong or elliptic,
finely toothed leaflets, 2.5 to 5
cm long. The plants have male
and female flowers. Each sex
occurs on a separate plant
with flowering occurring at
any season (mostly September
through October). The flower
clusters are 5 to 7 cm long. The
male and female flowers are
similar. Both are white (2 mm in
diameter) and are made up of
5 parts with 10 stamens in 2
rows of five. The flowers also
have a lobed disc within the
stamens. The fruits are in clus-
ters which are glossy, green
and juicy at first, becoming
bright red on ripening. The red
skin dries to become a papery
shell surrounding the seed. The
seed is dark brown and 3 mm
in diameter.

History
This species is a native of Argen-
tina, Paraguay and Brazil. It is


thought to have been intro-
duced into Florida by 1842-
1849 as a cultivated ornamental
plant. Schinus is the Greek
word for Mastic-tree, a plant
with resinous sap, which this
genus resembles. The species
name terebinthifolius is a combi-
nation of the genus name
terebinthus and the Latin name
Folia, leaf. It refers to the leaves
of this plant which resemble
those of species in the genus
Terebinthus.
Habitat
Schinus is widely distributed in
Florida and sensitive to cold
temperatures so it is limited to
protected areas in central
Florida. It is an aggressive in-
vader of disturbed habitats.
Brazilian Pepper-tree success-
fully colonizes several native
plant communities: hammocks,
pinelands and mangrove forests.

Biology
Seedlings are flood tolerant but
rapid change of water level up
or down causes some mortality.
About 20 percent of seedlings
exposed to fire resprout. Flower-
ing occurs from September
through November. Male flow-


Photogph: Ted J. Stetl
Seedling
The cotyledons are simple with
both the apex and the base
having an obtuse outline. The
margin Is generally curved
Inward on one side. The first
true leaves are simple with a
toothed margin. The later leaves
are compound.









ers last only 1 day Female
flowers last up to 6 days and
are insect pollinated. Fruits are
usually mature by December.
Birds and mammals are the
chief means of dispersal. Viabil-
ity is 30 to 60 percent which
can last up to 2 months with
0.05 percent at 5 months.
Germination is enhanced by


scarification with a dilute acid.
The dilute acid may have the
same effect as the acids found
in an animal's digestive tract.
Many native species have a
lower percentage of germina-
tion than Schinus. The higher
germination percentage com-
bined with the animal dispers-
ing agents may explain its


colonization in native plant
communities. Seedlings have a
high rate of survival and some
can be found all year. Any
break in the canopy can be
utilized. Reproduction can
occur 3 years after germination.
Some trees can live for about
35 years.
-David W. Hall and Vernon V. Vandlver, Jr.
IFAS/Unlverslty of Florida/1989










Bagpod

(Bladderpod)
Sesbania vesicaria (Jacq.) Ell.
Leguminosae (Fabaceae)
Bean Family


nIotograph: Janet Easterday


Mature Plant
S. vesicaria is a robust, smooth-
stemmed annual, growing to 4
m tall, with few or no branches.
The stem tips have dense white
hairs. The leaves are alternately
arranged and are once even-
pinnately compound. The leaves
may be as long as 30 cm. Each
leaf may have from 20 to 40
leaflets. The leaflets have
smooth margins and are nar-
rowly oblong to elliptic in
shape. The leaflets may be up
to 3 cm long and 6 mm wide
and very hairy when expand-
ing, becoming smooth at matur-
ity. The stipules are not persis-
tent. The flowers occur in the
axils of the leaves. The bracts
and bractlets are not persistent.
The calyx tube is hairy when
young, becoming smooth at
maturity, and is 2 to 3 mm
long. The corolla is 6 to 9 mm
long. The petals are yellow and
quite variable in color, often
tinged with pink or red. The
fruit is a dry, smooth, inflated
pod, from 3 to 6 cm long and
1.5 to 2 cm wide. Each pod
contains 1 or usually 2 seeds.


History
Sesbania is from the word
Sesban which is thought to be
the name of an Arabic genus.
Vesicaria is from Latin, means
inflated or bladder-like, and
refers to the fruit.

Habitat
S. vesicaria occurs in pastures,
along fencerows and generally
in any disturbed, moist to wet
area throughout Florida, north-
ward to North Carolina, west-
ward to Texas, primarily on the
coastal plain, and inland to
Oklahoma and Arkansas.

Biology
Bagpod frequently grows in
mixed populations with S.
exaltata.
-Davd W. Hall and Vrnon V. Vandler, Jr.
IFAS/Unmivlty ofFloridan/989


Photograph: John D. Tobe
Seedling
The stems are thick and smooth.
The cotyledon blades are ob-
long, thick and smooth, with a
mldveln depression visible on
the upper surface and the mid-
vein distinct on the lower sur-
face. The cotyledon petioles are
short. The leaves are alternate.
The first leaf is simple, Each
additional leaf is even-pinnately
compound with 8 or more leaf-
lets. The Individual leaflets have
short, minute stalks. The central
rachis has a groove on the
upper surface. The petiole has
two stlpules. The opposite leaf-
lets are pressed together during
early development.









Hemp

Sesbania

Sesbania exaltata (Raf.) Cory
(Sesbania macocarpa Muhl., may
be the correct name for this
species.)
Leguminosae (Fabaceae)
Bean Family


Photogaph: John D. Tobe
Mature Plant
S exaltata is a robust annual
with smooth stems growing to
4 m tall and with few or no
branches. The stem tips have
few or no hairs. The leaves are
alternately arranged and are
once even-pinnately compound.
The leaves may be as long as
30 cm. Each leaf may have
from 20 to 70 leaflets. The
leaflets have smooth margins
and are narrowly oblong to
linear-elliptic or linear with a
point on the tip. The leaflets
may be up to 3.5 cm long and
8 mm wide, and are smooth
and somewhat waxy beneath.
The stipules are not persistent.
The flowers occur in the axils
of the leaves. The calyx tube is
smooth and 3 to 4 cm long.
The corolla is 1.5 to 2.0 cm
long. The petals are yellow and
are often streaked or spotted
with purple. The fruit is a dry,
smooth, linear pod from 10 to
20 cm long and 3 to 4 mm
broad. Each pod contains from
30 to 40 seeds.
History
Sesbania is from the word
Sesban which is thought to be
the name of an Arabic genus.
The Latin word exaltata means


tall and refers to the height of
the plant. The Latin words
macro, large, and carpo, fruit,
refer to the long pod.
Habitat
S. exaltata occurs along ditches,
roadsides, fields, disturbed
sites, river banks and lake
shores throughout Florida
westward to southern Califor-
nia and northward to New
bYrk. It is also found in Central
America.
Biology
Hemp Sesbania germinated at
temperatures ranging from 15
to 40 C. Optimal growth oc-
curred from 30 to 35" C. The
seed coats are from 59 to 63
percent impermeable. These
can be made permeable by
acid scarification or mechanical
scarification. This results in 98
percent germination. Increased
germination also resulted from
an increase in oxygen concen-
tration (from 0 to 100 percent).
Induced moisture stress by os-
motic pressure from 0 to -8
bars resulted in a decreased
germination from 95 percent at
0 bars to 21 percent at -8 bars.
After burial 18 percent of the
seeds were still viable after 51/2
years.
-DIvld W. Hall and Vrnon V. Vandlver, Jr.
IFASUnlvelty of Florida/1989


Photograph: P. Bunny Stafford
Seedling
The stems are thick and smooth
with two faint ridges along the
upper portion. The cotyledon
blades are oblong, thick and
smooth, with a mldveln that Is
indistinct near the base on the
upper surface but distinct on
the lower surface. The petioles
are short and flat with smooth
ridges across the upper surface.
The leaves are alternate with
the first leaf being simple. All
additional leaves are even-pin-
nately compound with 6 to 8 or
more leaflets. The Individual
leaflets have very short, minute
stalks. The central rachls has a
groove on the upper surface.
The petiole has 2 stipules. The
developing opposite leaflets are
Initially pressed together.










Horse-nettle

Solanum carolinense L.
Solanaceae
Nightshade Family


Photograph: Teresa Hallyy

Mature Plant History


S. carolinense is a rhizomatous
perennial that grows erect and
can reach a height of approxi-
mately 1 meter. The stems are
spiny and roughly hairy with
star-shaped hairs. The leaves
are elliptic to ovate and mea-
sure approximately 1.9 to 14.4
cm in length and 0.4 to 8 cm in
width. They are wavy and
coarsely toothed with spines
along the main veins. The few
to many white, violet or blue
flowers which may form a
cluster at maturity are terminal.
The sepals measure from 2 to 7
mm and often have small spines
on the surface. The petals are
ovately lobed and can reach a
diameter of 3 cm. The anthers
are erect and about 6 to 8 mm
in length. The fruit is a berry I
to 2 cm in diameter, globose,
green and smooth, turning
yellow and wrinkling upon
maturation. The seeds are
numerous, 1.5 to 2.5 mm in
diameter, round or broader at
the tip in outline, flat in cross
section, orange to dark or light
yellow, and their surfaces are
smooth and glossy.


Solanum is an ancient Latin
name for an unknown species
of plant. The species name
carolinense is an English word
put into Latin. It simply means
of Carolina, where the first
specimen of this species was
collected.

Habitat
This weed can be found on
roadsides and in sandy open-
ings and waste areas through-
out Florida to Texas, and in the
Northeast to Canada.

Biology
The foliage and fruits are used
medicinally. The fruits are
poisonous and have caused the
death of cattle.
-DavldW. Hall and Vernon Vandlvhr Jr.
IFA/Unlvrslty of Florlda/1989

Seedling
The stem (hypocotyl) Is stout,
green with purple tinges, and
densely covered with short,
stiff, slightly downwardly an-
gled, spreading hairs. The cotyle-
don blades are glossy green on
the upper surface, light green
on the lower surface, smooth
on both surfaces, with short
gland-tipped hairs along the


Photograph: Ted J. Stelter


Seedling [continued]
margins, and have the mldveln
evident on the upper surface as
a depression and on the lower
surface as a slight ridge. The
petioles are flat on the upper
surface and smooth. The first
leaves are alternate with blades
that are dark green on the
upper surface and light green
on the lower surface. A sparse
cover of appressed, unbranched
and star-shaped hairs is on the
upper surface of the older
leaves. The fourth and all other
leaves are slightly undulate or
lobed on the margins. The
petioles are flat on the upper
surface and these too are cov-
ered with star-shaped hairs. The
stem Is green, becoming purple
with age.









Florida

HBetony

A Stachys floridana Shuttlew.
Labiatae (Lamiaceae)
Mint Family


Mature Plant
Florida Betony is a square-
stemmed, erect, hairy perennial
which spreads by seeds,
rhizomes and tubers. The tubers
are segmented and resemble a
rattlesnake's white rattle, usu-
ally up to 4 cm long and about
1 cm wide, although they may
be up to 8 cm long. The indi-
vidual segments are usually
shorter than broad. The stems
may grow to about 0.5 m tall.
The simple leaves are opposite
on the stem and have petioles
up to 3.5 cm long. The leaf
blades may be up to 5.5 cm
long and 2.7 cm wide. The leaf
base ranges from heart shaped
to blunt. The leaf margin has
teeth. The flowers occur in
clusters of 3 to 6 in the upper
leaf axils. The sepals are fused,
forming a tube which is hairy,
up to 7 mm long, and with 5
lanceolate lobes. The petals are
fused, 2-lipped, and up to 1.3
cm long. The upper lip is some-
what erect. The lower lip is
3-lobed. The 4 stamens and the
2-cleft stigma extend outside
the tube. The fruit is a
schizocarp (a dry fruit that
splits into 2 halves, each half
up to 1.7 mm long). The seeds
are about 1 mm long.


History
The name for the genus,
Stachys, is derived from the
Greek word stachys which
means an ear of wheat or a
spike, as the flowers appear to
be arranged in such a manner.
The Latinized English species
name floridana refers to the
fact that it was first named
from a Florida collection. This
species was thought to be
restricted (endemic) to Florida
until the 1940s or 1950s.

Habitat
This weed occurs on wet sandy
soils, lawns, roadsides and
thickets throughout Florida
westward to Texas and north-
ward to Virginia.
Biology
The most important means of
spread is by tubers in soil
moved with ornamentals or
turf.
--Daid W. Hall and Vrwnon V. andlv, Jr.
IFASUnvernlty of FlorIda/1989


Photograph: MIhael Rfle
Seedling
The seedlings are rarely encoun-
tered. Virtually all the spread Is
by tubers. The young sprouts
from the tubers have leaves on
opposite sides at the stem. The
stem Is usually square and quite
hairy.













University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs