Commercial Timbers


H. G. Richter and M. J. Dallwitz

Mildbraediodendron excelsum Harms (Muyati)

Nomenclature etc. FABACEAE-CAESALPINIOIDEAE. Trade and local names: bolélembé, bolélélembé (CD); muyati (UG). Not protected under CITES regulations.

Tree. Geographic distribution: tropical Africa.

General. Growth ring boundaries indistinct or absent. Heartwood basically brown brown and yellow, without streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Density 0.9–1 g/cm³. Typically variegated surface due to abundant light-coloured paratracheal parenchyma.

Vessels. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows. Two distinct vessel diameter classes absent. Average tangential vessel diameter 125–160–250 µm; diameter of vessel lumina: large. Average number of vessels/mm² 2–4; vessels per square millimetre very few. Average vessel element length 200–260 µm. Average vessel element length short. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9–11 µm, medium to large, vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Tyloses in vessels absent. Other deposits in heartwood vessels present (light yellow and nearly black).

Tracheids and fibres. Fibres very thick-walled. Average fibre length 630–970–1220 µm. Average fibre length medium. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.

Axial parenchyma. Axial parenchyma banded or not banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide. Marginal parenchyma bands often discontinuos and with irregular spacing. Axial parenchyma paratracheal. Paratracheal axial parenchyma aliform to confluent. Aliform parenchyma lozenge. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4. Paratracheal parenchyma abundant, primarily of the confluent type.

Rays. Rays 9–12 per tangential mm, multiseriate (also if only few), 1–2(–3) cells wide, narrow (2–3 seriate). Height of large rays up to 500 µm. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent.

Storied structures. Storied structure present, all rays storied, axial parenchyma storied, vessel elements storied, fibres storied or not storied. Arrangement of tiers regular (horizontal or straight) to irregular. Number of ray tiers per axial millimetre 4–5.

Secretory structures. Intercellular canals absent.

Cambial variants. Included phloem absent.

Mineral inclusions. Crystals present, prismatic, located in axial parenchyma cells. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Frequency of crystals extremely variable from specimen to specimen, often concentrated in marginal parenchyma. Silica not observed.

Illustrations. • Transverse section. Mildbraediodendron excelsum. • Tangential section. Mildbraediodendron excelsum. • Radial section. Mildbraediodendron excelsum.

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.’.