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Erythrina excelsa Baker

Protologue
Oliv., Fl. trop. Afr. 2: 183 (1871).
Family
Papilionaceae (Leguminosae - Papilionoideae, Fabaceae)
Origin and geographic distribution
Erythrina excelsa is widespread from Côte d’Ivoire and Mali east to Kenya and south to Zambia.
Uses
The wood is popular in Uganda for making drums, and is also used for stools, shields, mortars and carving for the tourist industry. It is used as fuelwood and for making charcoal. The bark sap is administered as an antidote for snakebites. Erythrina excelsa is locally planted as an ornamental and roadside tree.
Properties
The wood is yellow-white, lightweight, soft and easy to work. Isoflavonoids have been isolated from the bark.
Botany
Deciduous medium-sized tree up to 30(–45) m tall; bole straight, branchless for up to 20 m, up to 80(–250) cm in diameter, armed with woody, conical spines, sometimes with steep buttresses up to 7 m high; bark surface smooth, pale, inner bark yellow; twigs armed with prickles. Leaves alternate, 3-foliolate; stipules triangular, up to 4 mm long, persistent; petiole 4–21 cm long, often prickly, rachis 2–8.5 cm long, with large glands at base of petiolules, stipels 2–3.5 mm long, petiolules 6–12 mm long; leaflets elliptical to ovate or oblong-elliptical, 7–23.5 cm × 3.5–16.5 cm, rounded to slightly cordate at base, acute or shortly acuminate at apex, initially hairy especially below but glabrescent, pinnately veined with c. 9 lateral veins. Inflorescence an axillary or terminal, erect, compact false raceme 10–35 cm long; bracts up to 1 cm long, early deciduous. Flowers bisexual, papilionaceous; pedicel 4–8 mm long; calyx spathe-like, glabrous or slightly hairy, split at one side, tube 1–2 cm long, limb 1–3 cm long, at apex with 2 acute teeth up to 8 mm long; corolla orange-red to scarlet red or coral-red, standard 2–4 cm × 1.5–2.5 cm, reflexing with age, wings 8–11 mm long, keel 6–10 mm long; stamens 10, fused to c. halfway but 1 almost free; ovary superior, narrowly cylindrical-oblong, 1-celled, style glabrous. Fruit a linear-oblong spirally twisted pod up to 20 cm long, markedly constricted between the seeds, densely brown hairy, opening by 2 valves, up to 10-seeded. Seeds 11–16 mm long, orange-red, with whitish scar.
Trees of Erythrina excelsa grow very fast. They usually flower when they are quite leafless. The flowers contain much nectar and are visited by sunbirds and bees.
Erythrina comprises approximately 120 species: about 30 in continental Africa, 6 in Madagascar, 70 in tropical America and 12 in tropical Asia and Australia.
Ecology
Erythrina excelsa is usually found in riverine and swamp forest, up to 1500 m altitude.
Management
Erythrina excelsa is propagated by seed, but seeds are liable to insect attack, even while still on the tree. It can also be propagated by cuttings and by collecting wildlings. Cuttings are used for planting as living fence material. Planted trees can be managed by pollarding.
Genetic resources and breeding
Erythrina excelsa is widespread, but seems to be uncommon or even rare in many parts of its distribution area. In some regions it is reported to be common, e.g. in the forest belt near Lake Victoria in Uganda. In regions in Uganda where the wood is commonly used in the drum-making industry, the number of mature trees has decreased significantly.
Prospects
As is the case in many Erythrina species, Erythrina excelsa deserves more attention in tropical Africa as an indigenous multipurpose tree, combining ornamental, auxiliary and timber values. Planting should be encouraged, especially in regions with heavy exploitation of natural populations for making drums.
Major references
• Burkill, H.M., 1995. The useful plants of West Tropical Africa. 2nd Edition. Volume 3, Families J–L. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 857 pp.
• Katende, A.B., Birnie, A. & Tengnäs, B., 1995. Useful trees and shrubs for Uganda: identification, propagation and management for agricultural and pastoral communities. Technical Handbook 10. Regional Soil Conservation Unit, Nairobi, Kenya. 710 pp.
• Mackinder, B., Pasquet, R., Polhill, R. & Verdcourt, B., 2001. Leguminosae (Papilionoideae: Phaseoleae). In: Pope, G.V. & Polhill, R.M. (Editors). Flora Zambesiaca. Volume 3, part 5. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 261 pp.
Other references
• Akoègninou, A., van der Burg, W.J. & van der Maesen, L.J.G. (Editors), 2006. Flore analytique du Bénin. Backhuys Publishers, Leiden, Netherlands. 1034 pp.
• Eggeling, W.J. & Dale, I.R., 1951. The indigenous trees of the Uganda Protectorate. Government Printer, Entebbe, Uganda. 491 pp.
• Fomum, Z.T., Ayafor, J.F., Ifeadike, P.N., Nkengfack, A.E. & Wandji, J., 1986. Erythrina studies. Part 3. Isolation of an isoflavone from Erythrina senegalensis and Erythrina excelsa. Planta Medica 1986(4): 341.
• Gillett, J.B., Polhill, R.M., Verdcourt, B., Schubert, B.G., Milne-Redhead, E., & Brummitt, R.K., 1971. Leguminosae (Parts 3–4), subfamily Papilionoideae (1–2). In: Milne-Redhead, E. & Polhill, R.M. (Editors). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 1108 pp.
• Hauman, L., Cronquist, A., Boutique, R., Majot-Rochez, R., Duvigneaud, P., Robyns, W. & Wilczek, R., 1954. Papilionaceae (troisième partie). In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Homès, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 6. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. 426 pp.
• Lovett, J.C., Ruffo, C.K., Gereau, R.E. & Taplin, J.R.D., 2006. Field guide to the moist forest trees of Tanzania. [Internet] Centre for Ecology Law and Policy, Environment Department, University of York, York, United Kingdom. http://www.york.ac.uk/ res/celp/webpages/projects/ecology/ tree%20guide/guide.htm. Accessed September 2007.
• Omeja, A.P., 2001. Impact of drum making on the wild population structure and supplies of selected tree species in Central Uganda. MSc. Thesis, Department of Botany, Faculty of Science, Makerere University, Kampala, Uganda. 110 pp.
• Omeja, A.P., Obua, J. & Cunningham, A., 2004. Regeneration, density and size class distribution of tree species used for drum making in central Uganda. African Journal of Ecology 42(2): 129–136.
Author(s)
R.H.M.J. Lemmens
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands


Editors
D. Louppe
CIRAD, Département Environnements et Sociétés, Cirad es-dir, Campus international de Baillarguet, TA C-DIR / B (Bât. C, Bur. 113), 34398 Montpellier Cedex 5, France
A.A. Oteng-Amoako
Forestry Research Institute of Ghana (FORIG), University P.O. Box 63, KNUST, Kumasi, Ghana
M. Brink
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
General editors
R.H.M.J. Lemmens
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
L.P.A. Oyen
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
J.R. Cobbinah
Forestry Research Institute of Ghana (FORIG), University P.O. Box 63, KNUST, Kumasi, Ghana

Correct citation of this article:
Lemmens, R.H.M.J., 2008. Erythrina excelsa Baker. In: Louppe, D., Oteng-Amoako, A.A. & Brink, M. (Editors). Prota 7(1): Timbers/Bois d’œuvre 1. [CD-Rom]. PROTA, Wageningen, Netherlands.