* Nematology Circular No. 79 (Botany 14)
Hand fern, Ophioglossum palmatum, endanger
and becoming extremely rare in FloridE
.gric. & Consumer Services
division l~Pgg ustry
red diversity Frid
University of florida
K. R. Langdon
The hand fern, Ophioglossum palmatum L., was described by Linnaeus in 1753 from
material collected in Santo Domingo, Dominican Republic. It was first discovered in
Florida along the Caloosahatchee River by A. W. Chapman in 1875. It has since been
found in numerous locations from Seminole and Manatee Counties south, usually near
the coast and only a few feet above sea level. The habitat for this fern in Florida
is almost exclusively in the detritus among the old leaf bases or "boots" of cabbage
palms, Sabal palmetto (Walter) Loddiges ex J. A. & J. H. Schultes, growing in low,
moist, shady hammocks. Clearing, drainage, fire, and collecting have eliminated the
hand fern from most of its former locations so that it is now extremely rare.
Fig. 1. Hand fern, Ophioglossum palmatum, growing on cabbage palm
(D.P.I. neg. no. 702301) (courtesy Eve A. Hannahs)
Contribution No. 231, Bureau of Nematology, P.O. Box 1269, Gainesville, FL 32602
DESCRIPtION: Roots cord-like; rhizome tuberous, globose, covered with wooly
scales; leaves fleshy, pendent, long petiolate, with blade divided into usually 2-7
lanceolate lobes or sometimes entire, cuneate; leaf and petiole combined up to 40 cm
long; up to 6 or rarely more erect or ascending sporophylls attached along petiole
margin near base of blade, 3-5 cm long, cylindric or cylindric-conic with 2 rows of
sporangia in 8-60 pairs.
. ,-DISCTSSION: The hand fern is extremely sensitive to any disturbance to its
habitat, particularly fire. With drainage of many of the swamps and hammocks where
this fern grows, fires are more frequent and severe. According to Small (1) "So
destructive have been the fires that in many localities where comparatively few
years ago the hand-fern could be gathered literally by the wagon load it is now
extinct." Since those words were written, the hand fern has been extirpated from a
number of additional sites. It is now found only rarely in a few sites.
Collectors are now probably an even greater threat to the hand fern than fire.
As an example, when the trail through Mahogany Hammock in Everglades National Park
was opened in April 1960, 3 trees in the hammock were known to bear the hand fern.
By June of that year none remained (2). The few remaining populations are restric-
ted to remote areas deep in the heart of almost inaccessible swamps and hammocks.
If the hand fern is to survive in Florida, these sites must be protected from fire
and the depredations of collectors.
Another serious problem is the fact that this fern is very difficult to grow in
cultivation because of its specialized habitat requirements. Collected plants
rarely survive for any extended period of time. Most collected plants, therefore,
are doomed to die.
The hand fern, though very rare now in Florida, does occur elsewhere in tropi-
cal America. Its range extends from Florida south through the Caribbean islands and
Central America to northern South America. It apparently is not particularly abun-
dant in any of these areas. With continued land development it will become in-
creasingly rare throughout its range.
1. Small, J. K. 1964 (1938). Ferns of the southeastern states. Hafner. New
2. Ward, D. B., Editor. 1979. Rare and endangered biota of Florida. Vol. 5.
Plants. University Presses of Florida. Gainesville. 175p.