Commercial Timbers


H. G. Richter and M. J. Dallwitz

Milicia excelsa (Welw.) C.C. Berg (Iroko, kambala)

Nomenclature etc. MORACEAE. Syn.: Chlorophora excelsa (Welw.) Benth., Morus excelsa Welw. Trade and local names: iroko (DE, FR, GB, NL, NG), kambala (GA, CG, CD), odum (GH, CI), abang, bang (CM), amoreira (AO), chamfutu (MZ), semli (LR), rokko (NG), lusanga (CD). Not protected under CITES regulations.

Tree. Geographic distribution: tropical Africa.

General. Growth ring boundaries indistinct or absent. Heartwood basically brown to yellow to green. Sapwood colour distinct from heartwood colour. Density 0.48–0.63–0.67 g/cm³.

Vessels. Wood diffuse-porous. Vessels in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 145–235–310 µm. Average number of vessels/mm² 1–3–10. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9–12 µm. Vessel-ray pits with reduced borders or apparently simple, rounded or angular, of uniform size or type, of the same type in adjacent elements. Tyloses in vessels present, thinwalled.

Tracheids and fibres. Fibres of medium wall thickness. Average fibre length 590–1320–2030 µm. Fibre pits common in both radial and tangential walls, simple to minutely bordered.

Axial parenchyma. Axial parenchyma banded (at irregular intervals). Axial parenchyma bands marginal (or seemingly marginal). Axial parenchyma paratracheal. Paratracheal axial parenchyma vasicentric, aliform, and confluent. Aliform parenchyma lozenge, or winged. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4.

Rays. Rays 3–9 per tangential mm, multiseriate (also if only few), 3–4 cells wide. Rays with multiseriate portions as wide as uniseriate portions present. Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows, mostly 1 marginal row of upright or square cells.

Secretory structures. Laticifers or tanniniferous tubes present (laticifers, sporadically).

Mineral inclusions. Crystals present, prismatic, located in ray cells and axial parenchyma cells. Crystals in procumbent ray cells not in radial alignment. Number of crystals per cell or chamber one, or more than one. Crystals in one cell or chamber of the same size, or of two distinct sizes. Silica not observed.

Illustrations. • Macro images. Milicia excelsa. Transverse. Tangential. • Transverse section. Milicia excelsa. • Tangemtial section. Milicia excelsa. • Radial section. Milicia excelsa. • Miscellaneous. Milicia excelsa. Latex tubes in rays. Crystals in marginal ray cells.

The interactive key allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, and geographical distribution.

Cite this publication as: ‘Richter, H.G., and Dallwitz, M.J. 2000 onwards. Commercial timbers: descriptions, illustrations, identification, and information retrieval. In English, French, German, Portuguese, and Spanish. Version: 25th June 2009.’.