Samanea saman (Jacq.) Merr.
Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.
- Folk Medicine
- Yields and Economics
- Biotic Factors
With a checkerd nomenclature, under Enterolobium in the Wealth of India,
Pithecellobium in Common Trees of Puerto Rico, and Samanea in Woody
Plants of Ghana, the rain tree is apparently widely traveled. Perhaps one of
its most important uses in Latin America is as a shade tree, especially in
parks, pastures, and roadsides. Improved growth, nutritive quality, protein
content, and yield have been demonstrated by Axonopus compressus, a
tropical forage grass, grown under Samanea. "The benefit by association
was presumptively attributed to nitrogen made available in the soil by
excretion or decomposition of the leguminous nodules." (Allen and Allen, 1981).
The tree house in Walt Disney's "Swiss Family Robinson" was built in a rain
tree 60 m tall with a canopy 80 m in diameter. Simon Bolivar is said to have
encamped his entire liberation army under the "saman de guerra" near Maracay,
Venezuela. In Malagasy, it is grown as shade tree for cacao, coffee,
patchouly, and vanilla. In Indonesia, it is recommended for nutmeg but not for
tea. In Uganda, it is considered good for coffee, bad for tea. According to
NAS (1980a), "Grass grows right up to the trunk because this species' leaflets
fold together at night and in wet weather, allowing the rain to fall through."
Like Acacia, Ceratonia, Prosopis, and Tamarindus, this produces
copious pods with a sweet pulp, attractive to children and animals alike. Pods
can be ground up and converted to fodder or for that matter alcohol as an
energy source. A lemon-like beverage can be made from the pulp. The wood is
soft, lightweight (spec. grav. 0.44; 720880 kg/m3) of medium to
coarse texture, fairly strong, takes a beautiful finish but is often
cross-grained and difficult to work. It is used for furniture, general
construction, and interior trim, for boxes and crates, panelling, plywood, and
veneer. Central American oxcart wheels are made from cross sections of trunks.
It is used for boat building in Hawaii, where it is also famous for making
"monkeypod" bowls. Shavings from the wood are used for making hats in the
Philippines. The tree yields a gum of inferior quality which could be used as
a poor man's substitute for gum arabic. Like most other mimosaceous trees,
this is an important honey plant. Rain tree is one host of the lac insect,
which, however, produces a poor quality lac, reddish and rather brittle
According to Hartwell (19671971), the root decoction is used in hot baths for
stomach cancer in Venezuela. Rain tree is a folk remedy for colds, diarrhea,
headache, intestinal ailments, and stomachache (Duke and Wain, 1981). The
alcholic extract of the leaves inhibits Mycobacterium tuberculosis
(Perry, 1980). The alkaloid fraction of the leaves is effective on the CNS and
PNS. In Colombia, the fruit decoction is used as a CNS-sedative. The leaf
infusion is used as a laxative (Garcia-Barriga, 1975). In the West Indies,
seeds are chewed for sore throat (Ayensu, 1981).
Per 100 g, the green leaf is reported to contain 47.8 g H2O, 10.2 g protein,
2.1 g fat, 22.2 g insoluble carbohydrate, 15.7 g fiber, and 2.0 g ash. On an
oven-dry basis, the leaves contain ca 3.2% N. Gohl, 1981 tabulates as follows:
Whole pods contain: moisture, 15.3; ash, 3.2; fat, 2.1; protein, 12.7; 11.4;
and carbohydrates, 55.3%. Kernels contain: moisture, 16.1; ash, 3.0; fat, 1.3;
protein, 10.6; CF, 10.8; and carbohydrates, 42.0%. The bark contains two
alkaloidsC8H17ON and C17H36ON3 (pithecolobine; LD50 in mice 40225
mg/kg)and a saponin (samarin), which yields on hydrolysis an aglucone of the
formula C23H36O4, arabinose, glucose and rhamnose. Samarin is an irritant to
isolated intestine. Other constituents identified in the bark are gallic acid,
glucose, sucrose, fatty acids and a phytosterol. Wood contains: lignin, 30.44;
cellulose, 50.89; a-cellulose, 38.35; and ash, 0.27% (C.S.I.R., 19481976). Hager's Handbook (List and Horhammer, 19691979) reports
hexacosanol, lupeol, a-spinasterol, octaconsanolic acid,
a-spinasterol-b-D-glucoside, a-spinasterone, and lupeone from the
rind, hentriacontane and octacosanol from the leaves; a-spinasterol, and
its b-D-glucoside, palmitic, and stearic acid from the seed kernel, three
flavonoids and kaempferol from the testae, and a-spinasterol and
octacosabolic acid from the wood.
Large umbraculiform tree to as much as 60 m tall, the crown to 80 m broad,
covering 1/5 hectare, trunk to 1.5 m DBH, unarmed, with gray rough furrowed
bark. Leaves alternate, evergreen, bipinnate, 2540 cm long, with 26 pairs of
pinnae, each of which bears 616 paired stalkless leaflets, with a glandular
dot between each pair. Flower heads clustered near the end of twigs, each
cluster on a green hairy stalk 710 cm long, with many small tubular
pinkish-green flowers, calyx and corolla 5-toothed. The many stamen united to
form a tube near their bases, seed pods oblong, flat, arcuate, black, 2030 cm
long, with a raised border, each with several oblong reddish-brown seeds ca one
Reported from the South American Center of Diversity, rain tree, or cvs
thereof, is reported to tolerate drought, poor soils, waterlogging and weeds.
(2n = 26)
Native from the Yucatan Peninsula and Guatemala to Peru, Bolivia, and Brazil.
Widely planted and naturalized elsewhere in continental tropical America from
Mexico southward, throughout the West Indies (except Bahamas), and in Old World
tropics. Grown also in southern Florida (Little and Wadsworth, 1964).
Ranging from Subtropical Very Dry to Moist through Tropical Dry to Moist Forest
Life Zones, rain tree is reported to tolerate annual precipitation of 6 to 25
dm (mean of 49 cases = 14.0), annual temperature of 21.6 to 28.5°C (mean of
36 cases = 25.8), and pH of 6 to 7.
Easily propagated from seeds and cuttings. Young specimens transplant easily.
Lopped for forage or timber at any time, it can be maintained at any height by
A full grown tree 15 years old is said to yield ca 200275 kg pods per season,
which translates to 10 MT/pods, if we can crowd 50 productive trees to the
hectare. A single tree 5 years old has been said to yield nearly 550 kg green
forage (assuming 50% moisture = ca 275 kg DM). Assuming 50 trees to the
hectare, that translates to nearly 14 mT forage in leaves.
According to figures in the Wealth of India, 10 MT pods would yield 1150 liters
of absolute alcohol, roughly 510 barrels ethanol/ha/yr. It is reportedly used
as an alcohol source in Colombia. Use of the wood as a fuel is not often
reported. In the Philippines, Quisumbing (1951) reports the branches and trunk
are used as firewood.
Browne (1968) lists: Fungi. Fomes annularis, Ganoderma australe, Ganoderma
lucidum. Coleoptera. Anomala antiqua, Apate monachus, Lepropus
chrysochlorus, Oncideres tessellata. Hemiptera. Ferrisia virgata,
Hemiberlesia lataniae, Icerya aegyptiaca, Icerya formicarum, Kerria lacca,
Ptyelus flavescens, Rastrococcus iceryoides. Isoptera. Coptotermes
amanii. Lepidoptera. Attacus atlas, Homona coffearia, Indarbela
quadrinotata, Melisomimas metallics. Mammalia. Callosciurus caniceps.
Also occuring on Samanea saman are Hypomyces haematococcus;
root knot nematodes, Meloidogyne sp.; and the leaf spot Microstroma
| || ||As % of dry matter|
| ||DM ||CP || CF ||Ash || EE ||NFF ||Ca ||P|
|Fresh twigs, late vegetative, Malaysia ||38.9 ||24.7 ||22.1 ||4.4 ||2.8 ||46.0 ||0.55 ||0.26|
|Fresh leaves, Thailand ||39.1 ||22.1 || 29.4 || 6.0 ||7.0 ||35.5 ||1.42 ||0.21|
|Fresh leaves, Trinidad ||34.4 ||30.0 ||29.0 || 3.5 ||3.5 ||34.0|
|Pods, Jamaica ||79.5 ||12.8 ||14.5 || 2.4 ||0.7 || 69.6 ||0.29 ||0.32|
|Pods, fallen, Trinidad ||85.0 ||18.0 ||10.9 || 4.6 ||1.4 ||65.1|
|Seeds, Jamaica ||86.5 ||31.6 ||14.0 ||4.3 ||6.0 ||44.1 ||0.16 ||0.34|
Complete list of references for Duke, Handbook of Energy Crops
- Allen, O.N. and Allen, E.K. 1981. The Leguminosae. The University of Wisconsin
Press. 812 p.
- Ayensu, E.S. 1981. Medicinal plants of the West Indies. Reference Publications,
Inc. Algonac, MI. 282 p.
- C.S.I.R. (Council of Scientific and Industrial Research). 19481976. The wealth
of India. 11 vols. New Delhi.
- Duke, J.A. and Wain, K.K. 1981. Medicinal plants of the world. Computer index
with more than 85,000 entries. 3 vols.
- Garcia-Barriga, H. 1975. Flora medicinal de Colombia. Botanica Medica. Talleres
Editoriales de la Imprenta Nacional. Bogota.
- Hartwell, J.L. 19671971. Plants used against cancer. A survey. Lloydia 3034.
- List, P.H. and Horhammer, L. 19691979. Hager's handbuch der pharmazeutischen
praxis. vols 26. Springer-Verlag, Berlin.
- N.A.S. 1980a. Firewood crops. Shrub and tree species for energy production.
National Academy of Sciences, Washington, DC.
- Perry, L.M. 1980. Medicinal plants of east and southeast Asia. MIT Press,
- Quisumbing, E. 1951. Medicinal plants of the Philippines. Tech. Bul. 16.
Philippine Department of Agriculture and Natural Resources, Manila.
Last update Friday, January 9, 1998 by aw