Commercial Timbers


H. G. Richter and M. J. Dallwitz

Baillonella toxisperma Pierre (Moabi)

Nomenclature etc. SAPOTACEAE. Trade and local names: adjap, ayap (CM); ayap (GQ); dimpampi (CG); m'foi (GA); muamba jaune (CD); African pearwood (GB). Not protected under CITES regulations.

Description based on 6 specimens. Tree. Geographic distribution: tropical Africa.

General. Growth ring boundaries distinct or indistinct or absent. Growth ring limits at times marked by an abrupt change in the distance between parenchyma bands. Heartwood basically brown to red, without streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Density 0.76–0.9 g/cm³.

Vessels. Wood diffuse-porous. Vessels arranged in diagonal and/or radial pattern, in multiples, commonly short (2–3 vessels) radial rows to radial rows of 4 or more. Radial/diagonal orientation of vessel groups not always very evident disposition en files radiales/obliques des vaisseaux pas toujours évidente. Average tangential vessel diameter 100–160 µm; diameter of vessel lumina: large. Average number of vessels/mm² 10–16; vessels per square millimetre few. Average vessel element length 500–900 µm. Average vessel element length medium. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 6–10 µm, medium, not vestured. Vessel-ray pits with distinct borders or with reduced borders or apparently simple, similar to intervessel pits or different from intervessel pits, rounded or angular or horizontal to vertical, of two distinct sizes or types in the same ray cell, of the same type in adjacent elements, located throughout the ray. Helical thickenings absent. Tyloses in vessels present, thinwalled.

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres of medium wall thickness to very thick-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres non-septate.

Axial parenchyma. Axial parenchyma banded. Axial parenchyma bands marginal (or seemingly marginal) or not marginal (or seemingly marginal), reticulate, fine, up to three cells wide, 6–7 per radial mm. Axial parenchyma apotracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 7–11. Unlignified parenchyma absent.

Rays. Rays 9–11 per tangential mm, multiseriate (also if only few), 1–3 cells wide, narrow (2–3 seriate). Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays of one size. Height of large rays up to 500 µm. Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows, mostly 2–4 marginal rows of upright or square cells to with more than 4 marginal rows of upright or square cells. Sheath cells absent. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent.

Storied structures. Storied structure absent.

Secretory structures. Oil and mucilage cells absent. Intercellular canals absent. Laticifers or tanniniferous tubes absent.

Cambial variants. Included phloem absent. Other cambial variants 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. Cystoliths absent. Silica present, as grains, in rays cells and in axial parenchyma. Silica grains in rays typically large and frequent in marginal cells, smaller and less frequent in procumbent body cells.

Physical and chemical tests. Froth test positive.

Illustrations. • Transverse section. Baillonella toxisperma. • Tangential section. Baillonella toxisperma. • Radial section. Baillonella toxisperma. • Silica in ray cells. Baillonella toxisperma. SiO2 particles in 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.’.