Commercial Timbers


H. G. Richter and M. J. Dallwitz

Antiaris africana Engl., A. toxicaria Lesch., A. welwitschii Engl. (Ako)

Nomenclature etc. MORACEAE. Trade and local names: Africa: ako (DE, CI, SN), antiaris (DE, GB), akede (CI), bonkonko (CD), chenchen (GH), kirundu (eAfr), mongodou, false oro (NG), vawi, diolosso (CM); Asia: ipoh, opas (ID, MY). Not protected under CITES regulations.

Tree. Geographic distribution: Burma (only A. toxicaria), or Thailand, Laos, Vietnam, Cambodia (only A. toxicaria), or Indomalesia (only A. toxicaria), or tropical Africa.

General. Growth ring boundaries indistinct or absent. Heartwood basically yellow to white or grey brown to yellow. Sapwood colour similar to heartwood colour. Density 0.4–0.45–0.5 g/cm³. Ribbon figure due to interlocked grain.

Vessels. Wood diffuse-porous. Vessels in multiples, commonly short (2–3 vessels) radial rows. Occasionally radial vessel groups of 4 and small clusters. Average tangential vessel diameter 155–200–245 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9 µm. Vessel-ray pits with reduced borders or apparently simple, rounded or angular to horizontal to vertical, of uniform size or type, of the same type in adjacent elements. Tyloses in vessels present, thinwalled. Other deposits in heartwood vessels vessel lines often appearing dark due to blue stain.

Tracheids and fibres. Fibres very thin-walled, or of medium wall thickness (medium wall thickness quite rare). Average fibre length 640–1050–1375 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres exclusively septate. Septate fibres evenly distributed.

Axial parenchyma. Axial parenchyma paratracheal. Paratracheal axial parenchyma vasicentric, aliform, and confluent (less frequently aliform and confluent). Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4(–8).

Rays. Rays multiseriate (also if only few), (1–)3–6 cells wide. 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 to mostly 2–4 marginal rows of upright or square cells.

Storied structures. Storied structure absent.

Secretory structures. Intercellular canals absent. Laticifers or tanniniferous tubes present. Latex tubes.

Mineral inclusions. Crystals present, prismatic and in other forms (small, mostly circular crytals), located in ray cells, axial parenchyma cells, and fibres (the latter reported only for A. toxicaria by Janssonius). Crystal-containing ray cells upright and/or square and procumbent. 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, or of two distinct sizes. Silica not observed.

Illustrations. • Macro images. Antiaris africana. Transverse. Radial. • Transverse section. Antiaris africana. • Tangential section. Antiaris africana. • Radial section. Antiaris africana.

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.’.