Commercial Timbers


H. G. Richter and M. J. Dallwitz

Ricinodendron heudelotii (Baill.) Pierre ex Pax (Erimado)

Nomenclature etc. EUPHORBIACEAE. Syn.: Ricinodendron africanum Muell. Arg., Jatropha heudelotii Baill. Trade and local names: erimado (NG); eho (CI); essessang (GA); wama (GH); nsezang (GQ); sanga-sanga (CG). Not protected under CITES regulations.

Tree. Geographic distribution: tropical Africa.

General. Growth ring boundaries indistinct or absent. Heartwood basically white or grey. Sapwood colour similar to heartwood colour. Density 0.22–0.35(–0.4) g/cm³.

Vessels. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows to radial rows of 4 or more. Average tangential vessel diameter 200–320(–380) µm; diameter of vessel lumina: very large. Average number of vessels/mm² 2–7; vessels per square millimetre very few to few. Average vessel element length 450–800(–1000) µm. Average vessel element length medium to long. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) (10–)13–17 µm, large. Vessel-ray pits with reduced borders or apparently simple, rounded or angular, of the same type in adjacent elements or unilaterally compound and coarse. Helical thickenings absent. Tyloses in vessels present, thinwalled.

Tracheids and fibres. Fibres very thin-walled. Average fibre length 1450–1800(–2050) µm. Average fibre length long. Fibre pits mainly restricted to radial walls, simple to minutely bordered or distinctly bordered. Fibres non-septate.

Axial parenchyma. Axial parenchyma not banded. Axial parenchyma apotracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4–12.

Rays. Rays 7–12 per tangential mm, exclusively uniseriate. Height of large rays commonly 500 to 1000 µm to commonly over 1000 µm (up to 1.7 mm). Rays composed of a single cell type (homocellular), or two or more cell types (heterocellular); homocellular ray cells procumbent. Heterocellular rays with square and upright cells restricted to marginal rows, mostly 1 marginal row of upright or square cells.

Storied structures. Storied structure absent.

Secretory structures. Laticifers or tanniniferous tubes absent.

Mineral inclusions. Crystals present, prismatic, located in axial parenchyma cells. Crystal-containing axial parenchyma cells not chambered. Number of crystals per cell or chamber one, or more than one. Crystals in one cell or chamber of the same size. Silica not observed.

Illustrations. • Transverse section. Ricinodendron heudelotii. • Tangential section. Ricinodendron heudelotii. • Radial section. Ricinodendron heudelotii.

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.’.