Difference between revisions of "Drypetes gerrardii (PROTA)"

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Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Fruit
Carbohydrate / starch
Medicinal
Timber
Fuel
Food security

Drypetes gerrardii Hutch.

Protologue: Dyer, Fl. cap. 5(2): 405 (1920).

Family: Euphorbiaceae (APG: Putranjivaceae)

Synonyms

Drypetes battiscombei Hutch. (1924).

Vernacular names

Bastard white ironwood, forest ironwood, forest ironplum, hairy drypetes (En). Kihambie (Sw).

Origin and geographic distribution

Drypetes gerrardii is widespread from southern Sudan, Uganda and Kenya south to Angola, Zimbabwe, Mozambique, eastern South Africa and Swaziland.

Uses

The wood known in Kenya as ‘munyenye’ and in southern Africa as ‘white bastard wood’ is locally used, mainly for poles in construction, and for joinery, furniture, tool handles and utensils. It is suitable for flooring, mine props, ship building, vehicle bodies, sporting goods, boxes, crates, agricultural implements and turnery. Locally in South Africa small Drypetes gerrardii trees with a bole diameter of 3–10 cm are popular for poles in house building and fencing. The wood is also used as firewood and for charcoal production.

In traditional medicine, a root decoction is taken to treat stomach-ache, and ground roots and leaves are administered with water to treat gonorrhoea. The flowers provide nectar for honey bees.

Properties

The heartwood is whitish, turning pale yellowish to greyish upon exposure, with occasional brownish streaks, and indistinctly demarcated from the wide sapwood. The grain is straight, occasionally slightly interlocked, texture fine and even.

The wood is medium-weight to heavy, with a density of 710–815 kg/m³ at 12% moisture content, and hard. It air dries slowly but well, with only slight end-checking and warping. The rates of shrinkage during drying are quite high. Once dry, the wood is stable in service. At 12% moisture content, the modulus of rupture is 147 N/mm², modulus of elasticity 18,230 N/mm² and compression parallel to grain 68 N/mm².

The wood saws and works moderately well with machine tools. It planes to a smooth surface. It has a tendency to split upon nailing and screwing, and pre-boring is advised. The peeling and slicing characteristics are not favourable. The wood is moderately durable. It is liable to termite attack, but in South Africa it has been recorded to be resistant to termites. The sapwood is liable to Lyctus attack, and the wood is susceptible to marine borers. The heartwood is resistant to treatment with preservatives, the sapwood is moderately resistant.

Several triterpenoids, a steroid and a flavone dimer have been isolated from the leaves.

Description

Evergreen, dioecious shrub or small to medium-sized tree up to 20(–35) m tall; bole branchless for up to 10 m, straight, up to 40(–50) cm in diameter, often fluted at base or with sharp buttresses; bark surface grey or greyish brown, usually smooth, sometimes flaking in rounded scales, inner bark yellowish white to orange with white flecks; crown dense and narrow with more or less horizontal branches; twigs drooping, greyish, finely hairy. Leaves alternate, simple; stipules triangular, c. 1 mm long, soon caducous; petiole 3–10 mm long; blade ovate to rhombic-elliptical or lanceolate, 2–14(–17) cm × 1–7(–9) cm, cuneate to rounded and asymmetrical at base, acute to acuminate at apex, margins toothed to nearly entire, thin-leathery, yellowish hairy along midrib or nearly glabrous, pinnately veined with 5–9 pairs of lateral veins. Flowers unisexual, regular, 4-merous; pedicel up to 4 mm long; sepals rounded, c. 3 mm in diameter, whitish yellow, densely yellowish hairy; petals absent; male flowers in an axillary few-flowered fascicle, with 4 stamens c. 3 mm long, disk 4-lobed; female flowers solitary, with shallowly cup-shaped disk, ovary superior, densely hairy, 2-celled, styles 2, free, reflexed, up to 1.5 mm long. Fruit an obovoid to nearly globose, slightly 2-lobed, fleshy drupe 1–1.5 cm long, short-hairy, yellowish to reddish-orange when ripe, indehiscent, 1–2-seeded. Seeds compressed-ovoid, c. 1 mm long, brownish with whitish streaks.

Other botanical information

Drypetes gerrardii is variable and some varieties have been distinguished, mainly based on leaf sizes and hairiness of young shoots and petioles.

Drypetes comprises about 210 species and is distributed throughout the tropics and subtropics. About 60 species occur in continental Africa and about 15 in the Indian Ocean islands. The wood of several other Drypetes spp. is used locally in tropical Africa.

Drypetes afzelii

Drypetes afzelii (Pax) Hutch. is a shrub or small tree up to 10 m tall, occurring in West Africa, from Sierra Leone to Ghana. Its greyish to pale brown wood is hard, durable and quite resistant to termites and probably used for construction. The gum from the bole is rubbed on the body because of its aromatic scent. Drypetes afzelii is classified as vulnerable in the IUCN Red List because it is uncommon and suffered from decline of its habitat, i.e. wet evergreen forest.

Drypetes arguta

Drypetes arguta (Müll.Arg.) Hutch. is a shrub or small tree up to 8 m tall, occurring from Tanzania south to eastern South Africa. In South Africa small logs, with a mean length of 150 cm and mean diameter of 22 cm, are used for wall laths in building traditional houses, and the wood is used for sticks. The fruits are edible and used to make an intoxicating drink.

Drypetes aubrevillei

Drypetes aubrevillei Leandri is a small to medium-sized tree up to 25 m tall with bole up to 50 cm in diameter. It is found in West Africa, from Sierra Leone to Ghana. Its pale yellow wood is heavy, with a density of about 960 kg/m³ at 12% moisture content, and hard. It is used in house construction. The bark is used in traditional medicine; it is applied externally to treat bronchitis, lumbago, rheumatism and kidney pain, and is taken as expectorant.

Drypetes aylmeri

Drypetes aylmeri Hutch. & Dalziel is a small tree up to 13 m tall, with bole up to 25 cm in diameter. It is also found in West Africa, from Sierra Leone to Ghana. Its whitish wood is hard, durable and quite resistant to termites, and used in house construction.

Drypetes bathiei

Drypetes bathiei Capuron & Leandri is a shrub up to 4 m tall, occurring in northern and eastern Madagascar. Its hard wood is used for construction, tool handles and sticks.

Drypetes caustica

Drypetes caustica (Frapp. ex Cordem.) Airy Shaw is a small to medium-sized tree up to 20 m tall, endemic to Réunion and Mauritius. The wood has been used for construction, but Drypetes caustica has become rare and exploitation should be discouraged.

Drypetes floribunda

Drypetes floribunda (Müll.Arg.) Hutch. is a small tree up to 10 m tall, occurring from Senegal east to DR Congo in dry forest and savanna. Its whitish wood is hard and used in house construction and for poles, and also as firewood. The pulp of the orange-red fruits is edible, and twigs are used as chew-sticks for cleaning the teeth.

Drypetes gilgiana

Drypetes gilgiana (Pax) Pax & K.Hoffm. is a shrub or small tree up to 10(–15) m tall, with bole up to 25 cm in diameter. It occurs from Senegal east to Cameroon in various forest types. Its pale brown wood is hard, and used in traps for animals and probably also for construction. The pulp of the orange-red fruits is sweet and edible, but not commonly consumed.

Drypetes gossweileri

Drypetes gossweileri S.Moore is a medium-sized tree up to 30(–40) m tall, with bole up to 100(–120) cm in diameter, occurring from Nigeria east to the Central African Republic and DR Congo. Its pale yellowish brown wood, with a density of 760–800 kg/m³ at 12% moisture content, is commonly used in house building and for joinery. However, the applications of the bark in traditional medicine are more important.

Drypetes mossambicensis

Drypetes mossambicensis Hutch. is a shrub or small to medium-sized tree up to 20 m tall, with bole up to 60 cm in diameter. It is found in woodland, often along rivers, in Malawi, Zambia, Zimbabwe, Mozambique and northern South Africa. The pale brown to yellowish brown wood, which has a density of about 970 kg/m³ at 12% moisture content, is used for household utensils and ornaments. The fruits are edible and locally popular.

Drypetes parvifolia

Drypetes parvifolia (Müll.Arg.) Pax & K.Hoffm. is a shrub or small tree up to 6 m tall. It occurs in West Africa from Sierra Leone to Nigeria, and in East Africa in Kenya and Tanzania. Its wood is locally used in house construction, mainly for poles.

Drypetes roxburghii

Drypetes roxburghii (Wall.) Hurus. originates from tropical Asia and has been introduced in some regions of West and East Africa, where it is mainly planted as ornamental shade tree. In tropical Asia its wood is used for construction and turnery, whereas the leaves and fruits are used in traditional medicine and the leaves as forage.

Anatomy

Wood-anatomical description (IAWA hardwood codes):

• Growth rings: 2: growth ring boundaries indistinct or absent.
• Vessels: 5: wood diffuse-porous; (10: vessels in radial multiples of 4 or more common); 13: simple perforation plates; 22: intervessel pits alternate; 25: intervessel pits small (4–7 μm); 30: vessel-ray pits with distinct borders; similar to intervessel pits in size and shape throughout the ray cell; 41: mean tangential diameter of vessel lumina 50–100 μm; 47: 5–20 vessels per square millimetre.
• Tracheids and fibres: 61: fibres with simple to minutely bordered pits; 66: non-septate fibres present; 70: fibres very thick-walled.
• Axial parenchyma: 76: axial parenchyma diffuse; 77: axial parenchyma diffuse-in-aggregates; (86: axial parenchyma in narrow bands or lines up to three cells wide); 87: axial parenchyma reticulate; (93: eight (5–8) cells per parenchyma strand); 94: over eight cells per parenchyma strand.
• Rays: 97: ray width 1–3 cells; (100: rays with multiseriate portion(s) as wide as uniseriate portions); 102: ray height > 1 mm; 106: body ray cells procumbent with one row of upright and/or square marginal cells; 107: body ray cells procumbent with mostly 2–4 rows of upright and/or square marginal cells; 116: ≥ 12 rays per mm.
• Mineral inclusions: (136: prismatic crystals present); (137: prismatic crystals in upright and/or square ray cells); (138: prismatic crystals in procumbent ray cells).

(P. Mugabi, P.E. Gasson & E.A. Wheeler)

Growth and development

Young leaves of Drypetes gerrardii are reddish. Larvae of the butterfly Coeliades libeon feed on the leaves. In southern Africa, flowering trees have been recorded from September to November, and ripe fruits from October to April. The fruits are eaten by animals such as birds and monkeys, which serve as seed dispersers.

Ecology

Drypetes gerrardii occurs in evergreen forest and riverine forest, sometimes also in scrub vegetation, at 600–2300 m altitude. It is usually found in more dry forest types, but occasionally also in more humid rainforest.

Propagation and planting

The 1000-seed weight is about 12 g. In an experiment in Uganda, seeds germinated on average 39 days after sowing at a low germination rate of 17.5%.

Management

Small-sized Drypetes gerrardii trees (up to 10 cm in bole diameter) are locally common in the forest understory in South Africa, with recorded average densities of 130 stems per ha, of which an average of 18 stems per ha are harvested to serve as poles. Trees can be coppiced. In South Africa nearly 50% of cut stems showed coppice regeneration.

Genetic resources

Drypetes gerrardii is not only widespread but also locally common; its exploitation seems to be moderate, and therefore it is not threatened by genetic erosion, although locally over-exploitation for poles and firewood may occur.

Prospects

Drypetes gerrardii and other Drypetes spp. do not play a role on the international timber market, and in view of their usually small bole size it is unlikely that this will change. However, the usually quite heavy, hard and fairly durable wood is locally important for construction, especially for poles, and research on growth rates and regeneration is recommended to draw up directives for proper management practices to ensure sustainable production.

Major references

• Beentje, H.J., 1994. Kenya trees, shrubs and lianas. National Museums of Kenya, Nairobi, Kenya. 722 pp.

• Bolza, E. & Keating, W.G., 1972. African timbers: the properties, uses and characteristics of 700 species. Division of Building Research, CSIRO, Melbourne, Australia. 710 pp.

• Boudreau, S., Lawes, M.J., Piper, S.E. & Phadima, L.J., 2005. Subsistence harvesting of pole-size understorey species from Ongoye Forest Reserve, South Africa: Species preference, harvest intensity, and social correlates. Forest Ecology and Management 216: 149–165.

• Burkill, H.M., 1994. The useful plants of West Tropical Africa. 2nd Edition. Volume 2, Families E–I. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 636 pp.

• Chikamai, B.N., Githiomi, J.K., Gachathi, F.N. & Njenga, M.G., undated. Commercial timber resources of Kenya. Kenya Forestry Research Institute (KEFRI), Nairobi, Kenya. 164 pp.

• Coates Palgrave, K., 1983. Trees of southern Africa. 2nd Edition. Struik Publishers, Cape Town, South Africa. 959 pp.

• Palmer, E. & Pitman, N., 1972–1974. Trees of southern Africa, covering all known indigenous species in the Republic of South Africa, South-West Africa, Botswana, Lesotho and Swaziland. 3 volumes. Balkema, Cape Town, South Africa. 2235 pp.

• Radcliffe-Smith, A., 1996. Euphorbiaceae, subfamilies Phyllantoideae, Oldfieldioideae, Acalyphoideae, Crotonoideae and Euphorbioideae, tribe Hippomaneae. In: Pope, G.V. (Editor). Flora Zambesiaca. Volume 9, part 4. Royal Botanic Gardens, Kew, Richmond, United Kingdom. pp. 1–337.

• Hyde, M.A. & Wursten, B., 2010. Drypetes. [Internet ] Flora of Zimbabwe: Genus page. http://www.zimbabweflora.co.zw/ speciesdata/ genus.php?genus_id=835. May 2010.

• Widodo, S.H., 2001. Crescentia L. In: van Valkenburg, J.L.C.H. & Bunyapraphatsara, N. (Editors). Plant Resources of South-East Asia No 12(2): Medicinal and poisonous plants 2. Backhuys Publishers, Leiden, Netherlands. pp. 191–194.

Other references

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• Coode, M.J.E., 1982. Euphorbiacées. In: Bosser, J., Cadet, T., Guého, J. & Marais, W. (Editors). Flore des Mascareignes. Familles 153–160. The Sugar Industry Research Institute, Mauritius, l’Office de la Recherche Scientifique Outre-Mer, Paris, France & Royal Botanic Gardens, Kew, Richmond, United Kingdom. 117 pp.

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• Grace, O.M., Prendergast, H.D.V., Jäger, A.K. & van Staden, J., 2002. Bark medicines in traditional healthcare in KwaZulu-Natal, South Africa: an inventory. South African Journal of Botany 69(3): 301–363.

• Ichikawa, M., 1987. A preliminary report on the ethnobotany of the Suiei Dorobo in northern Kenya. African Study Monographs, Supplement 7: 1–52.

• Liu, K., Eastwood, R.J., Flynn, S., Turner, R.M. & Stuppy, W.H., 2008. Seed Information Database Release 7.1, May 2008. [Internet] http://data.kew.org/ sid/. May 2010.

• Long, C., 2005. Swaziland’s flora – siSwati names and uses. [Internet] http://www.sntc.org.sz/ flora/clusagelist.asp?uid=1&pg=14. May 2010.

• 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://celp.org.uk/ projects/ tzforeco/. April 2011.

• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.

• Ng’ang’a, M.M., Chhabra, S., Langat-Thoruwa, C., Hussain, H. & Krohn, K., 2008. Chemical constituents from the leaves of Drypetes gerrardii. Biochemical Systematics and Ecology 36(4): 320–322.

• Obiri, J. & Lawes, M., 2003. Using the spatial grain of regeneration to select harvestable tree species in subtropical forest. Forest Ecology and Management 184: 105–114.

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Sources of illustration

• Noad, T. & Birnie, A., 1989. Trees of Kenya. A fully illustrated field guide. Nairobi, Kenya. 281 pp.

• Troupin, G., 1983. Euphorbiaceae. In: Troupin, G. (Editor). Flore du Rwanda. Spermatophytes. Volume 2. Agence de Cooperation Culturelle et Technique. Tervuren, Belgium. pp. 189–242.

Author(s)

• E.A. Obeng

Forestry Research Institute of Ghana (FORIG), University P.O. Box 63, KNUST, Kumasi, Ghana

Correct citation of this article

Obeng, E.A., 2011. Drypetes gerrardii Hutch. [Internet] Record from PROTA4U. Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. <http://www.prota4u.org/search.asp>.

Accessed 18 December 2024.

• See the Prota4U database.