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Prota 7(1): Timbers/Bois d’œuvre 1 Record display |
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Protologue Ann. Inst. Bot.-Géol. Colon. Marseille sér. 3, 3: 32 (1915). Family Sapotaceae Origin and geographic distribution Lecomtedoxa klaineana occurs in southern Cameroon, Equatorial Guinea and Gabon. Uses The wood (trade name: ogoumo) is used for carpentry. It is suitable for heavy construction, heavy flooring, ship and boat building, vehicle bodies, furniture, sliced veneer, interior trim, joinery, railway sleepers, poles, mine props and toys and novelties. In Gabon the latex has been administered as a tonic to women after childbirth. Properties The heartwood is reddish brown, distinctly demarcated from the whitish sapwood. The grain is fairly straight, texture fine. The wood is heavy, with a density of 900–1040 kg/m³ at 12% moisture content. It dries slowly and needs to be dried with care. The shrinkage rates are high, from green to oven dry 5.9–7.8% radial and 9.0–11.8% tangential. At 12% moisture content, the modulus of rupture is 180–232 N/mm², modulus of elasticity 13,600–20,300 N/mm², compression parallel to grain 75–91 N/mm², shear 8.9–18.9 N/mm², cleavage 26–39 N/mm and Chalais-Meudon side hardness 4.8–17.9. The wood saws slowly, and has a moderate blunting effect on saws and other tools, although silica is absent. The latex may gum up sawteeth and tool edges. The wood planes fairly easily with a smooth finish and takes a good polish. It tends to split on nailing and pre-boring is needed. The gluing properties are satisfactory. The wood can be used for sliced veneer, but rotary peeling is difficult. It is durable and resistant to fungi, dry-wood borers and termites. It is resistant to impregnation with preservatives. Adulterations and substitutes The wood is similar to several other heavy Sapotaceae woods, e.g. those of Autranella congolensis (De Wild.) A.Chev. and Baillonella toxisperma Pierre, which both occur in the same region as Lecomtedoxa klaineana. Description Medium-sized to large tree up to 40 m tall; bole straight and cylindrical, branchless for up to 25 m, up to 120 cm in diameter, often with broad and steep buttresses; outer bark reddish brown, scaly, inner bark pinkish brown, containing white latex; crown hemispherical; young branches glabrous. Leaves arranged spirally, clustered at the ends of branchlets, simple and entire; stipules absent; petiole c. 2 cm long; blade elliptical to slightly obovate, 8–15 cm × 2.5–5.5 cm, cuneate at base, rounded to shortly acuminate at apex, leathery, glabrous, pinnately veined with 10–15 pairs of lateral veins and with small veins parallel to lateral veins. Flowers in fascicles in leaf axils, bisexual, regular, 5-merous, c. 5 mm long, pedicellate; sepals free, ovate; corolla with short tube and 5 lobes divided to near the base into 3 segments, white; stamens inserted at top of corolla tube, opposite each corolla lobe, alternating with lanceolate staminodes with a long point at apex; ovary superior, hairy, 5-celled, style long and slender. Fruit a boat-shaped capsule c. 5 cm × 2.5 cm in diameter, with leathery wall, dehiscent, 1-seeded. Seed slightly obliquely ellipsoid, flattened, c. 3 cm × 2 cm, yellowish brown, shiny, with a scar over almost the full length. Other botanical information Lecomtedoxa comprises 5 species and is restricted to a small part of Central Africa, with most species in Gabon. It is poorly known, but seems most closely related to Neolemonniera, which is similar in flower and fruit structure, but differs by its leaf striations and presence of stipules. Lecomtedoxa nogo (A.Chev.) Aubrév. (of which the illegitimate name Lecomtedoxa heitziana (A.Chev.) Aubrév. is possibly a synonym) differs from Lecomtedoxa klaineana in its larger leaves with small veins transverse to lateral veins. Its wood is probably used in the same way as that of Lecomtedoxa klaineana. Its seeds provide a cooking oil used in Gabon, although fresh seeds are reportedly toxic. Lecomtedoxa nogo is classified as vulnerable in the 2006 IUCN Red list of threatened species, due to its restricted distribution, which is limited to western Gabon. Anatomy Wood-anatomical description (IAWA hardwood codes): Growth rings: 2: growth ring boundaries indistinct or absent. Vessels: 5: wood diffuse-porous; 7: vessels in diagonal and/or radial pattern; 13: simple perforation plates; 22: intervessel pits alternate; (23: shape of alternate pits polygonal); (24: intervessel pits minute (≤ 4 μm)); 25: intervessel pits small (4–7 μm); 31: vessel-ray pits with much reduced borders to apparently simple: pits rounded or angular; 32: vessel-ray pits with much reduced borders to apparently simple: pits horizontal (scalariform, gash-like) to vertical (palisade); (33: vessel-ray pits of two distinct sizes or types in the same ray cell); 42: mean tangential diameter of vessel lumina 100–200 μm; 47: 5–20 vessels per square millimetre; 56: tyloses common. 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; 107: body ray cells procumbent with mostly 2–4 rows of upright and/or square marginal cells; 108: body ray cells procumbent with over 4 rows of upright and/or square marginal cells; 115: 4–12 rays per mm. Mineral inclusions: 136: prismatic crystals present; 142: prismatic crystals in chambered axial parenchyma cells. (E. Ebanyenle, A.A. Oteng-Amoako & P. Baas) Growth and development The fruits of Lecomtedoxa klaineana ripen in October–December. They are eaten by monkeys, which may serve as seed dispersers. Ecology Lecomtedoxa klaineana occurs in primary rainforest. Handling after harvest The freshly cut logs are too heavy to float in water and cannot be transported by river. Genetic resources Lecomtedoxa klaineana has a limited area of distribution. Although it may be locally dominant, it is in general uncommon. This makes it liable to genetic erosion and attention is needed to sufficiently protect this species. Prospects Lecomtedoxa klaineana has few prospects as a commercial timber tree. It is an uncommon species of limited distribution, and focus should be on its protection instead of commercialization. Major references • Aubréville, A., 1961. Sapotacées. Flore du Gabon. Volume 1. Muséum National d’Histoire Naturelle, Paris, France. 162 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. • de Saint-Aubin, G., 1963. La forêt du Gabon. Publication No 21 du Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 208 pp. • Normand, D. & Paquis, J., 1976. Manuel d’identification des bois commerciaux. Tome 2. Afrique guinéo-congolaise. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 335 pp. • Raponda-Walker, A. & Sillans, R., 1961. Les plantes utiles du Gabon. Paul Lechevalier, Paris, France. 614 pp. • Takahashi, A., 1978. Compilation of data on the mechanical properties of foreign woods (part 3) Africa. Shimane University, Matsue, Japan, 248 pp. Other references • Aubréville, A., 1964. Sapotacées. Flore du Cameroun. Volume 2. Muséum National d’Histoire Naturelle, Paris, France. 143 pp. • InsideWood, undated. [Internet] http://insidewood.lib.ncsu.edu/search/. Accessed May 2007. • Pennington, T.D., 1991. The genera of Sapotaceae. Royal Botanic Gardens, Kew, Richmond, United Kingdom and the New York Botanical Garden, New York, United States. 295 pp. • Tailfer, Y., 1989. La forêt dense d’Afrique centrale. Identification pratique des principaux arbres. Tome 2. CTA, Wageningen, Pays Bas. pp. 465–1271. • Usongo, L.I. & Amubode, F.O., 2001. Nutritional ecology of Preuss’s red colobus monkey (Colobus badius preussii Rahm 1970) in Korup National Park, Cameroon. African Journal of Ecology 39(2): 121–125. • Wilks, C. & Issembé, Y., 2000. Les arbres de la Guinée Equatoriale: Guide pratique d’identification: région continentale. Projet CUREF, Bata, Guinée Equatoriale. 546 pp. Sources of illustration • Aubréville, A., 1961. Sapotacées. Flore du Gabon. Volume 1. Muséum National d’Histoire Naturelle, Paris, France. 162 pp. • de Saint-Aubin, G., 1963. La forêt du Gabon. Publication No 21 du Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 208 pp. • World Conservation Monitoring Centre, 1998. Lecomtedoxa nogo. In: IUCN. 2006 Red list of threatened species. [Internet] http://www.iucnredlist.org. Accessed March 2007. Author(s)
Editors
Correct citation of this article: Lemmens, R.H.M.J., 2007. Lecomtedoxa klaineana (Pierre ex Engl.) Dubard. In: Louppe, D., Oteng-Amoako, A.A. & Brink, M. (Editors). Prota 7(1): Timbers/Bois d’œuvre 1. [CD-Rom]. PROTA, Wageningen, Netherlands. |
wild
1, base of bole; 2, leaf; 3, fruits; 4, seeds.Redrawn and adapted by Iskak Syamsudin |