Commercial Timbers


H. G. Richter and M. J. Dallwitz

Guibourtia conjugata (Bolle) J. Léonard (Black chacate)

Nomenclature etc. FABACEAE-CAESALPINIOIDEAE. Syn.: Gorskia conjugata Bolle, Copaifera conjugata O. Ktze., C. gorskiana Benth. Trade and local names: black chacate (trade); tsaura-heis, stakate (MZ). Not protected under CITES regulations.

Tree. Geographic distribution: tropical Africa (East Africa).

General. Growth ring boundaries indistinct or absent. Heartwood basically brown green, with streaks. Sapwood colour distinct from heartwood colour. Density 0.95–1.1 g/cm³.

Vessels. Wood diffuse-porous. Vessels in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 60–110 µm. Average number of vessels/mm² 25–60. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 6–9 µm, vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings absent. Other deposits in heartwood vessels present (yellowish brown).

Tracheids and fibres. Fibres very thick-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.

Axial parenchyma. Axial parenchyma banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide. Axial parenchyma paratracheal. Paratracheal axial parenchyma aliform. Aliform parenchyma lozenge. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4–5.

Rays. Rays 7–11 per tangential mm, multiseriate (also if only few), 2–4 cells wide. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent.

Storied structures. Storied structure absent.

Secretory structures. Intercellular canals 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. Crystal containing cells of normal size, or enlarged (idioblasts). Silica not observed.

Illustrations. • Transverse section. Guibourtia conjugata. • Tangential section. Guibourtia conjugata. • Radial section. Guibourtia conjugata.

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.’.