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Kukachka, B. Francis ( Bohumil Francis ), 1915-
Forest Products Laboratory (U.S.)
University of Wisconsin
U.S. Dept of Agriculture, Forest Service, Forest Products Laboratory ( Madison, Wis )
Publication Date:

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All applicable rights reserved by the source institution and holding location.
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aleph - 29320491
oclc - 243859560
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Full Text
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Revised November 1958

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No. 1787

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Dicorynia guianensis Amsh.
Family: Leguminosae-Caesalpiniaceae


B. FRANCIS KUKACHKA, Forest Products Technologist

Forest Products Laboratory,- Forest Service
U. S. Department of Agriculture


Angleique has for many years been incorrectly identified with the botanical
name Dicorynia paraensis Benth. It differs from this species and from other
described species of Dicorynia in the structure of the flowers and its re-
stricted range of growth. Presently known as Dicorynia guianensis, angelique
occurs only in French Guiana and Surinam. Dicorynia paraensis occurs along
the Rio Negro and its tributaries in Brazil's Amazonas Territory. Aside from
angelique, or basra locus as it is also known, the characteristics and proper-
ties of the various Dicorynia species are practically unknown at this time.

Angelique is well known in the producing areas for its strength and inherent
natural durability, but its highly desirable characteristics have only recent-
ly come to the attention of the United States trade. Small quantities are
currently entering the United States, but it is expected that imports will
gradually increase as the wood becomes better known.

Distribution and Habitat

Commercial stands of angelique occur in Surinam and French Guiana. In Surinam
the main stands are found between the Coppename and Marewijne Rivers on higher
ground not subjected to flooding. In French Guiana it is most common in the
western part of the country in the valleys of the Sinnamary, Mana, and Maroni

The Tree

The average height of the trees from the buttress to the first branches is
about 95 feet, and the average diameter is about 24 inches. It is considered

-Maintained at Madison, Wis., in cooperation with the University of Wisconsin.

Rept. No. 1787 (Revised)


a large tree and attains a maximum height of 150 feet and a diameter of 5
feet measured above the low buttresses.

The Wood

Because of the variability in color between different trees, three forms or
types are recognized by the producers. Heartwood that is russet colored when
freshly cut and becomes superficially dull brown on drying, commonly with a
purplish cast, is referred to as angelique gris. Heartwood that has a more dis-
tinctly reddish cast and frequently shows wide bands of purplish color is
called angelique rouge. And grayish-white colored wood, which apparently
comes from trees that are late in forming typical heartwood, is called angelique
blanc. The wood of angelique blanc contains abundant starch deposits, and
in this respect possesses the characteristics associated with sapwood.

Only the gris and rouge types are imported into the United States and generally
no differentiation is made between them. They are delivered without any limi-
tation as to maximum allowable percentage of one or the other.

Gross Features

The grain is generally straight or slightly interlocked. The texture (size
of pores) is about equal to that of African limba (Terminalia superba Engl.
& Diels) and somewhat coarser than that of American black walnut (Juglans
nigra L.). Flat-sawn surfaces usually show a pattern produced by the wood
parenchyma bands, which appear violet colored against the background color
of the wood. Storied elements of the wood produce a ripple mark pattern on
the side-grain surfaces, but this is very small. Quartered material shows
a more or less distinctive stripe associated with interlocked grain. The
wood surfaces may appear rather dull, but a definite golden subluster is one
of the distincitve features of this species.

Mechanical Properties

The mechanical properties of angelique are given in table 1 as compared with
those of teak (Tectona grandis L.F.) and white oak (Quercus alba L.). The
values for angelique are based on tests made at Yale University on two trees
from Surinam and three trees from French Guiana (1, 5). The comparative teak
values are from Tropical Woods ( ) and the white oak values from the Wood Hand-
book ).

Underlined numbers in parentheses refer to Literature Cited at end of text.

Rept. No. 1787


Angelique is superior to teak and white oak, when either green or air dry,
in all properties except tension perpeiid ic-iluar to the grain, in which it is
surpassed by both.

Mechanical tests made on the three forms of angelique show no significant

Machining Properties

Sawing and other machining properties vary among the different forms of
angelique and are reportedly due to differences in density, moisture content,
and silica content. Angelique rouge is reported to be the easiest to saw and
the blanc form the most difficult; the latter also tends to produce lumber
with fuzzy surfaces. Sawing is least difficult when the wood is in the green
condition, although considerable dulling of the saw does occur. After the
wood is thoroughly air dried or kiln dried, it can be worked effectively only
with carbide-tipped tools. A planer cutting angle of 150 is said to be suit-
able for working this species.

The wood finishes smoothly and is moderately easy to glue.


Duke University found that 4/4, 6/4, and 8/4 stock air seasoned well during
the period of 2 months in which the average temperature was 6l F. and the
average relative humidity was 58 percent. During this period green boards of
the above thicknesses, which varied between 67 and 92 percent moisture content,
were dried to a 15 to 25 percent range with only mild end checking and with
slight cup in the unrestrained boards on the top of the pile. Air-dried 4/4
stock was kiln dried to 8 percent without degrade on a normal hardwood schedule.
However, it was found necessary to use a very mild schedule for kiln drying
green stock to avoid collapse.

One of the producers of angelique has reported successful use of a kiln schedule
given in table 3 for green 4/4 flooring stock. The drying time is 21 to 24
days. The temperature during the initial steaming is high enough to cause col-
lapse in collapse-prone materials, so caution should be used if this procedure
is followed. The producer reported that the cooling-off period was necessary
to avoid bowing and crooking when the material was manufactured into flooring.
Perhaps a good conditioning treatment, such as is given in Forest Products
Laboratory Report 1791 (5), would achieve the same result.


Shrinkage values for angelique are given in table 2.

Rept. No. 1787


Decay Eesistance

Soil-block tests performed at Yale University (1, 2) indicate that angelique
is somewhat superior to teak and considerably superior to white oak in re-
sisting white rot fungi. In resistance to brown rot it was inferior to teak
but better than white oak. These comparisons pertain only to heartwood; sap-
wood is not decay resistant.

In tests made at the U. S. Forest Products Laboratory, the angelique samples
sustained such small amounts of decay by even the most active fungus that it
can be unqualifiedly classified for general consideration as very resistant.
It would be expected to have superior resistance to fungus damage both in
ground contact and in above-ground service. The test data reveal it to be com-
parable to black locust (Robinia pseudoacacia L.) in this respect.

With respect to commercial heating, the studies indicate that steaming of boat
frames may lower the decay resistance of some woods moderately. Angelique was
by far the least subject to heating effects of the nine durable woods tested
at the U. S. Forest Products Laboratory.

Marine Borer Resistance

Angelique has a favorable reputation as resistant to marine borers in the
Guianas, Panama Canal Zone, France, and the Netherlands. Wood after 15 years'
exposure in borer-infested waters at Balboa, Canal Zone, showed little pholad
attack and no significant damage by teredos (2).

Tests conducted at Harbor Island, N. C., and in Hawaiian waters generally con-
firm the favorable reputation of angelique in this regard. After 10 months'
exposure at Harbor Island, small specimens showed no evidence of marine borer
activity and after 15 months only moderate attack by teredo and pholads. This
performance surpassed that of teak, and under the same conditions white oak
specimens were heavily attacked within 6 months (6). Edmondson reports
angelique as showing no infestation by teredo and limnoria after an exposure
of 5 years in Hawaiian waters (2).

Termite Resistance

Experimental data on the termite resistance of angelique are rather meager.
Wolcott's data (7) rate angelique as 44, which is comparable to walnut and
white oak, with teak rated at 80 in its resistance to the West Indies termite.
Local reputation indicates that the wood has considerable resistance to termite
attack and that the rouge form is superior to the others.

Rept. No. 1787

Abrasion Resistance

Tests indicate that angelique is superior to teak and white oak in resisting
abrasion. Service trials on the landing decks of aircraft carriers show that
angelique wears at least as well as teak under these rigorous conditions.

Weathering Ability

When exposed to weathering without a protective coating, angelique develops
characteristic hairline checks that cover practically all of the surface. This
checking does not appear to become more extensive with time and is not dis-
qualifying for most structural uses. The heartwood is quite resistant to
moisture absorption and in this respect is comparable to white oak.

Fastening Strength

The Material Laboratory, New York Naval Shipyard, found that angelique holds
wood screws at withdrawal loads about one-third greater than those of teak
and white oak. A similar relationship could be expected to apply for drift
bolts, lag screws, and other types of fastenings, depending on frictional re-

Silica Content

The high degree of resistance of angelique to marine borer attack has been
generally attributed to the relatively high silica content of the wood. This
is one of the very few American legumes that accumulate silica, and in Dicorynia
it occurs in the vertical parenchyma cells and in the marginal cells of the
wood rays. The individual particles are generally about 0.001 inch in diameter.
It has been reported that the rouge form lacks silica; however, every authentic
specimen of all forms of angelique examined at the U. S. Forest Products Labora-
tory was found to contain silica. Judging from the reports of a number of in-
vestigators, the silica content is extremely variable and may account for the
variation in machlnability and borer resistance. Tests on individual specimens
show a range of variation from 0.20 to 2.92 percent of the weight of the dry
wood in the three forms of angelique.

Silica determinations made on the three forms of angelique at the U. S. Forest
Products Laboratory are given in table 4.


Angelique is available in thicknesses from 4/4 to 16/4 and in average widths
of about 8 inches; infrequently, boards are cut to a width of 18 inches. Poles
and piling are readily available in 40- to 60-foot lengths. Timbers may be

Rept. No. 1787


obtained in sizes up to 16 by 16 inches; however, the average for timbers is
more commonly about 10 by 10 inches in lengths up to 533 feet.

Quartered lumber for ship and boat decking may be obtained in lengths of 14
feet and more, averaging 16 feet, and in widths up to 6 inches. Small quanti-
ties of wider material can be obtained on special order.

Lumber suitable for hull planking, sheathing, and inner planking is available
in widths up to 10 inches, since flat-sawn material is permitted in these cate-
gories. Stress-rated grades may be obtained in lengths up to 18 feet and
widths up to 10 inches and in thicknesses of 2, 3, and 4 inches. Larger sizes
can usually be provided on special order.


Its strength and durability combined make angelique especially suitable for
heavy construction, harbor installations, bridges, heavy planking for pier
and platform decking, and railroad bridge ties. The heartwood is particularly
suitable for ship decking, planking, boat frames, and underwater members. At
the present time, small quantities of flooring are entering the United States
market, and the wood is undoubtedly suitable for many other building uses.

Identifying Features

The characteristic color of angelique and the presence of ripple marks will
generally separate this wood from those commonly used for heavy construction
and ship building. The ripple marks are best seen on flat-sawn surfaces, and
may be easily seen with the unaided eye. The ripples occur at the rate of 50
to 60 per inch along the grain. One Amazonian species (Androcalymma glabri-
folium Dwyer) resembles angelique very closely. It, however, lacks the ripple
marks and silica that are characteristic of angelique. The presence of silica
in the vertical parenchyma and the marginal cells of the wood rays further in-
sures the separation of angelique from other leguminous woods.

Known Producers at Time of Publication

Bruynzeel Surinam Plywood and U. S. Representative
Lumber Co. Ltd. D. J. K. M. Ramondt
Paramaribo, Surinam 5365 Sunset Avenue
Hapeville, Georgia
French Guiana Timbers
475 Fifth Avenue Greenheart (Demerara)
New York 17, N. Y. Inc.
52 Vanderbuilt Avenue
New York 17, N. Y.

Rept. No. 1787


Known Importers at Time of Publication

J. H. Monteath Co.
2500 Park Avenue
New York 51, N. Y.

Schroeder Lumber Co.
5401 Lawndale Avenue
Houston, Texas

Tropical and Western Lumber Co.
Box 58422, Vernon Station
Los Angeles 58, Calif.

Rept. No. 1787


Literature Cited

(1) Dickinson, F.

(2) Edmondson, C.

(3) Torgeson, 0.

E., Hess, R. W., and Wangaard, F. F.
Properties and Uses of Tropical Woods, I. Trop. Woods
No. 95, PP. 65-69. June 1. Yale University, New Haven,

Resistance of Woods to Marine Borers in Hawaiian Waters.
B. P. Bishop Museum, Bull. 217, pp. 1-91.

Schedules for the Kiln Drying of Wood.
U. S. Forest Products Laboratory Rept. No. 1791, 9 PP.,
Madison, Wis.

(4) U. S. Forest Products Laboratory
1955. Wood Handbook. Agric. Handbook No. 72, Forest Products
Laboratory, Forest Service, U. S. Dept. of Agric.,
Washington, D. C.

(5) Wangaard, F. F., and Muschler, Arthur
1952. Properties and Uses of Tropical Woods, III. Trop. Woods
No. 98, pp. 97-102. June 1. Yale University, New Haven,

(6) Wangaard, F. F.
1956. The Natural Marine Borer Resistance of Tropical American
Woods. Trop. Woods No. 105, pp. 58-43. October. Yale
University, New Haven, Conn.

(7) Wolcott, G. N.
1950. An Index to the Termite Resistance of Woods.
University of Puerto Rico Ag. Exp. St. Bull. No. 85.

Rept. No. 1787



Table l.--Mechanical properties of angelique and some comparable
hardwoods, teak and white oak

Property : Species

Angelique : Teak :White oak
(Dicorynia (Tectona: (Quercus
guianensiss) grandiss): alba)

Moisture content
Green........................percent: 81 : 52 : 68
Air dry...................... percent: 12 : 12 12

Specific gravity -- Based on volume :
when green and weight when ovendry : 0.62 : 0.58 : 0.60

Static bending :
Fiber stress at proportional limit
Green....................... p.s.i.: 8,560 : 7,250 4,700
Air dry.....................p.s.i. 12,980 8,160: 8,200
Modulus of rupture
Green.......................p.s.i.: 12,320 :11,380: 8,300
Air dry.....................p.s.i.: 18,590 :15,770 15,200
Modulus of elasticity
Green.................1,000 p.s.i. 1,920 1,580 1,250
Air dry...............1,000 p.s.i.: 2,240 : 1,670 : 1,780
Work to proportional limit per cu. in.: 2.06 : 1.89 : 1.08
Air per cu. in.: 3.96 : 2.51 : 2.27
Work to maximum load per cu. in.: 13.8 : 10.0 : 11.6
.Air per cu. in.: 14.2 : 19.3 : 14.8

Compression parallel to grain
Fiber stress at proportional limit: :
Green... ....................p.s.i. 5,060 : 4,120: 3,090
Air dry..................... p.s.i.: 7,160 : 5,,180: 4,760
Maximum crushing strength
5,750 5,490: 31560
Green p i 570..oe....ooe............p.s.i0: 5,750 5,9 5,56
Air dry.....................p.s.i.: 9,020 : 7,520 7,440

Hardness :
End :
Green................. 1,500 : 900 1,120
Air 2,010 : 1,010 1,520
Side : :
Green..........................b. 1,290 : 980 1,060
Air 1,510 : 1,100 1,360

Rept. No. 1787

(Sheet 1 of 2)

Table 1.--Mechanical properties of angelique and some comparable
hardwoods, teak and white oak (continued)

Property : Species

Angelique : Teak :White oak
(Dicorynia :(Tectona: (Quercus
guianensiss) grandiss): alba)

Compression perpendicular to grain
Stress at proportional limit
0.10 ,40 830
Green.......................p.s.i.: 1,110 : 1,040 850
Air dry.....................p.s.i.: 1,420 : 1,190 1,520

Tension perpendicular to grain : :
Green......................p.s.i. : 680 : 960 : 770
Air dry...................... p.s.i.: 540o 980 800

Shear :
Green.........................p.s.i.: 1,590 : 1,500: 1,250
Air dry......................p.s.i.: 1,780 : 1,560 2,000 151.2 : 84.4 144.9

At moisture content of 11.2 percent.

(Sheet 2 of 2)

Rept. No. 1787

Table 2 .--hrinka value for ,n' a lnqu,
teak, and w.hite oak

Species and source


:.Radial :Tangential:Volumetric
-- - -- - -- - -- - : - - -I- --- ---M --- lrM ---

:Percent: Percent

(Dicorynia g-uianensis)

(Tectona grandis)

White oak
(Quercus alba)
United States




Shrinkage values represent shrinkage
the ovendry condition expressed as
green dimension.

from the green to
a percentage of the

Rept. :o. 1787

: Percent







Table 3.--Kiln schedule for drying 4/4 angelique
for flooring

Time :Moisture : Temperature : Remarks
'content ----------------
: Dry-bulb:Wet-bulb:
---------------- -------------------------
Days: Percent F: F. : F.

:Above 50
: 50-25
: 25-20
: 20-15
: 15-10



:Initial steaming


Table 4.--Silica and ash content of angelique-

Silica : Ash :Percent silica
-------------------- ----------------- in ash
Range :Average: Range :Average:
Per e nt.. --P--r : Pr e- n ---- P .ercen-- ---
Percent :Percent: Percent :Percent:

Values based on ovendry weight of unextracted wood.

Rept. No. 1787

0.22-0.80 :
0.20-1.70 :
0.50-0.72 :

0.52 : 0.59-0.89 :
1.09 : 0.64-1.81 :
.51 : 0.45-0.77 :

0.77 :
1.1 :
.61 :

5 : ..........: ..... ",.:...... :Cooling




3ll B Ill 111111262 08927 221 4
3 1262 08927 2214


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