Commercial Timbers


H. G. Richter and M. J. Dallwitz

Aspidostemon spp. (Longotra)

Nomenclature etc. LAURACEAE. Important commercialized species: Aspidostemon louvellii, A. perrieri. Trade and local names: longotra (FR, MG); longotra mena, longotra fotsy (MG). Not protected under CITES regulations.

Description based on 15. Tree. Geographic distribution: Madagascar & other islands (endemic).

General. Growth ring boundaries indistinct or absent. Heartwood basically brown to red. Sapwood colour distinct from heartwood colour. Density 0.75–0.9 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 80–140(–170) µm; diameter of vessel lumina: large. Average number of vessels/mm² 20–32; vessels per square millimetre moderately numerous. Perforation plates simple or scalariform, with 2–10 bars. Scalariform perforations very few. Intervessel pits alternate, average diameter (vertical) 6–9 µm, medium. Pit cavities frequently with incrustations easily mistaken for vestures. Vessel-ray pits with reduced borders or apparently simple, horizontal to vertical. Helical thickenings rarely present or absent, only in narrow vessel elements, throughout the body of vessel elements. Tyloses in vessels present, thinwalled.

Tracheids and fibres. Fibres of medium wall thickness to very thick-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres exclusively septate. Septate fibres evenly distributed, or scattered near vessels and rays. 1–3 septae per fibre.

Axial parenchyma. Axial parenchyma paratracheal. Paratracheal axial parenchyma scanty. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 3–4.

Rays. Rays 7–13 per tangential mm, multiseriate (also if only few), 2–3(–5) cells wide, narrow (2–3 seriate). 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 1 marginal row of upright or square cells.

Storied structures. Storied structure present, all rays storied, axial parenchyma storied, vessel elements storied, fibres storied. Arrangement of tiers regular (horizontal or straight) to irregular. Number of ray tiers per axial millimetre 3.

Secretory structures. Oil and mucilage cells present, associated with axial parenchyma to fibres. Oil cells largely associated with rays (marginal rows), rarely with axial parenchyma or fibres.

Mineral inclusions. Crystals not observed. Silica not observed.

Physical and chemical tests. Heartwood not fluorescent.

Illustrations. • Transverse section. • Tangential section. Aspidostemon louvelii. • Radial section. Aspidostemon humbertiana. • Miscellaneous. Aspidostemon humbertiana. Oil cells in rays, associated with marginal and, occasionally, also in inner cell rows. Septate fibres, often restricted to the proximity of rays.

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.’.