Hymenaea courbaril: the flour tree
Hymenaea courbaril L. is a slow-growing large tree with a dense, handsome crown that produces high-quality wood (Timyan 1996). Its hard reddish-brown seeds are used by artisans in El Salvador to create jewelry and miniature paintings on the inside surface of the cut seeds. It is also the source of copal, a resin used for the production of varnish and home remedies.
Botany
Hymenaea courbaril, or copinol is a legume that belongs to the Caesalpinioideae subfamily (Berehdson, 1989). Its white flowers form dense panicles 10 to 15 cm wide and 10 to 15 cm long (Wistberger et al., 1982). Croat (1978) suggests that flowers are pollinated by bats. Copinol has compound leaves with 2 sessile leaflets that are shiny green. The indehiscent woody pods are 10 to 15 cm long and contain 3 to 4 hard reddish-brown seeds, imbedded in a sweet and odorous pulp (Allen and Allen, 1981, Arckcoll, 1984 ). Copinol grows up to 40 m tall and 1.5 m in diameter. The crown is spreading and sometimes the base develops buttresses. In Costa Rica, copinol blooms between February and May and fruit forms one to two months after flowering. Fruits remain on the tree for seven to ten months (Janzen, 1983).
Common names. Copinol and guapinol (El Salvador, Central America), or “flour tree” in the Nahuatl language, refers to the powdery pulp of the fruits (Wistberger et al., 1982). Other common names include: algarrobo, west indian locust, courbaril (Puerto Rico); rode lokus (Surinam); locust (Virgin Islands); and jatoba, jutai, or jatai (Brazil) (Little and Wadsworth, 1964; Oliveira et al., 1995).
Ecology
The native range of copinol includes Southern Mexico to Central America, northern Brazil, Bolivia and Peru. It is found from 0 to 900 m above sea level (Guatemala) near rivers or streams (Wistberger et al. 1982), on ridges and slopes, and high riverbanks (Chudnoff, 1984). The best growth in its native range occurs where rainfall is 1900 to 2150 mm/yr. It will grow in areas with rainfall as little as 1200 mm/yr. The mean annual temperatures within its native range are from 20 to 30°C. It grows on soils with pH 4.8 to 6.8. (Francis, 1990). It retains its leaves throughout the year (personal observations).
Uses
Wood. The wood is very durable (Timyan, 1996), hard and heavy (0.71 to 0.82 specific gravity). It is moderately difficult to work and resistant to termites, brown-rot and white-rot fungi (Chudnoff, 1984). In El Salvador, it has been used to make wheels for oxcarts (carretas), threading machines (telares), and for general construction (Witsberger et al., 1982). Other uses include furniture, boats, railroad ties, flooring, turnery, and cabinets (Chudnoff, 1984). The wood is suitable for firewood and charcoal. Copal, a resin exuded by the trunk and roots, is used to produce varnish, incense and local remedies.
Human food. The edible pulp is consumed locally in El Salvador and is sometimes sold in food markets. The pulp is used to prepare a sweet beverage (Wistberger et al., 1982). The pulp contains 3.2% sugar, 1.1% fat and 35.8% crude fiber (Francis, 1990).
Medicines. Tea made with the bark is used to control intestinal parasites, indigestion, and cure urinary infections. A liniment made with powdered copal and bark is used to treat external ulcers or rashes (Timyan, 1996). The leaves, cortex and roots of copinol contain tannins, glycosides, and sesquiterpenoids (Mena Guerrero, 1994).
Jewelry and crafts. In El Salvador, seeds are used to make jewelry and other small ornaments. The hard seeds are usually cut in half to work on the inside surface. In some cases the paintings are so small that artisans use magnifying glasses to work on them (personal observations).
Ornamental. Because of its large mature size, copinol should be planted only in parks and other open areas. Planting near buildings is not recommended because of its spreading roots.
Wildlife. Capuchin monkeys (Cebus apella) open the pods, consume the dry pulp, and drop the seeds (Galetti and Pedroni 1994). Agoutis (Dasyprocta punctata) feed on some seeds and bury the leftover seeds for future consumption. The scaly-headed parrot (Pionus maximiliani) may consume the seeds (Galetti, 1993). Flowers are a good source of nectar for bees and bats.
Silviculture
Copinol is propagated by seeds. Seedlings are propagated in nurseries before field establishment. Seeds are first scarified either by making a small cut with a file on the hard seed coat (Oliveria et al., 1994; El Salvador Forest Service) or with boiling water. In a boiling water study, seeds from a single tree were collected, dipped in boiling water for 0 to 60 seconds, soaked in water for 24 hours, and planted in sand (Orellana and Navarrete-Tindall, not published). Highest germination rates of 90 and 93% were observed at week six for seeds boiled for 25 and 30 seconds, respectively. The lowest germination rates of 30 and 67% were observed for untreated seeds and for seeds dipped in boiling water for 60 seconds, respectively. Under natural conditions, seeds germinate during the rainy season, sometimes inside the open pod (personal observations). There are about 250 seeds/kg (Francis, 1990).
Attina ants (Mycocepurus goeldii Forel) aid in germination by removing the fresh pulp around the seeds of broken pods (Oliveira et al., 1995). Curculionid larvae (Rhinocenus stigma and R.. transversalis ) develop inside the pods consuming the dry pulp and some seeds (Janzen 1983).
Growth and yield. Copinol is shade intolerant, but does require light side shade to produce clear boles for timber production (Francis, 1990). Growth is slow, rarely exceeding 1 m/yr. In a young natural stand in Puerto Rico, the mean diameter increment over a two-year period was 0.53 cm/yr. A 44-year-old plantation averaged about 14 m2 /ha of basal area. Planting density studies are needed, but an initial spacing of 3 m x 3 m and heavy thinning at 12 to 14 years (leaving 77 trees/ha) is suggested. The rotation length to grow trees to 50 cm d.b.h. on good sites is probably 45-65 years (Francis, 1990).
The El Salvador Forest Service is including copinol in reforestation programs and natural area planting.
Nodulation studies
Early studies by Allen and Allen (1939) and Bañados and Fernández (1954) reported that roots of copinol trees produced nodules. Recently Navarrete-Tindall et al. (1996), reported that 14 week-old copinol seedlings failed to nodulate when inoculated with 4 rhizobial strains of Gliricidia sepium. More research is being done to test cross-compatibility of copinol with rhizobial bacteria from other legumes.
Future research
More extensive studies are required in different environments to test for rhizobial infection. Provenance studies are necessary to select fast growers and high seed producers throughout its distribution range.
References
Allen, O.N. and E. K. Allen, 1981. The Leguminosae. The University of Wisconsin Press. pp. 337-338.
Arckcoll, D. B. 1984. Some leguminous trees providing useful fruits in the north of Brazil. Pesquisa Agropecuaria Brasilia. 19:231-234.
Bañados, L.L. and W. Fernández. 1954. Nodulation among the Leguminosae. The Philippine Agriculturist 37:528-533.
Behrendt, G., J.D. Brazier, and G.L. Franklin. 1968. Maderas nicaraguenses. Características y usos potenciales. FAO y Min. de Ag. y Ganadería. Honduras. pp. 21-22.
Berendsohn, W.G. 1989. Listado básico de la flora salvadorensis. Dicotyledonae. Familia 118:Leguminosae. Cuscatlania (El Salvador) I(2):118-8.
Chudnoff, M. 1984. Tropical timbers of the world. USDA Agriculture Handbook, 466 p.
Croat, T. A. 1978. Flora of Barro Colorado Island. Stanford University Press. California. p. 450.
Francis, J. K. 1990. Hymenaea courbaril (L.) Algarrobo, locust. SO-ITF-SM-27. Institute of Tropical Forestry. Rio Piedras, Puerto Rico. 5 p.
Galetti, M. 1993. Diet of the scaly-headed parrot (Pionus maximiliani) in a semideciduous forest in southeastern Brazil. Biotropica 25:419-425.
Galetti, M. and F. Pedroni. 1994. Seasonal diet of capuchin monkeys (Cebus apella) in a semideciduous forest in southeast Brazil. J. Trop. Ecol. 10:27-38.
Janzen, D.H. 1983. Seeding patterns of tropical trees. In: Tropical trees as living systems. P.B. Tomlinson and M. H. Zimmerman Eds. Cambridge University Press. pp. 83-124.
Little, E.L. and F.H. Wadsworth. 1964. Common trees of Puerto Rico and the Virgin Islands. Agriculture Handbook No.249. USDA Forest Service. pp.188-190.
Mena Guerrero, M.G. de. 1994. 2da. edición. Obtención y aprovechamiento de extractos vegetales de la flora salvadoreña. Editorial Universitaria. Universidad de El Salvador. pp. 141-142.
Navarrete-Tindall, N.E., J.W. Van Sambeek, and B. Klubek. 1996. Symbiotic promiscuity studies of rhizobial strains from Gliricidia sepium on legumes native to El Salvador. Forest, Farm, and Community Tree Research Reports 1:1-9.
Timyan, J. 1996. Bwa Yo: Important trees of Haiti. South East Consortium for International Development (SICID). Washington. 418 p.
Oliveira. P.S., M. Galetti, F. Pedroni, and L.P.C. Morellato. 1995. Seed cleaning by Mycocepurus goeldii ants (attini) facilitates germination in Hymenaea courbaril (Caesalpiniaceae).
Witsberger, D., D. Current, and E. Archer. 1982. Arboles del Parque Deininger. Ministerio de Educación, El Salvador. pp. 146-147.
The authors would like to acknowledge the USDA Forest Service in Carbondale, Illinois for their financial and logistic support and Universidad de El Salvador for their logistic support.
Written by Nadia E. Navarrete-Tindall, Department of Biology, New Mexico State University, Las Cruces, NM 88001 e-mail: ntindall@zianet.com and Mario A. Orellana Núñez, Facultad de Agronomía, Universidad de El Salvador, San Salvador, El Salvador. Material added by FACT Net staff.
A publication of the Forest, Farm, and Community Tree Network (FACT Net)