Commercial Timbers


H. G. Richter and M. J. Dallwitz

Anacardium spp. (Cashew, cajú)

Nomenclature etc. ANACARDIACEAE. A. occidentale L., A. giganteum Engl., A. spruceanum Benth., Anacardium spp. Trade and local names: cashew, pauji (IN). Not protected under CITES regulations.

Description based on 7 specimens. Tree. Geographic distribution: Caribbean, or Mexico and Central America to tropical South America.

General. Heartwood basically brown to yellow (russet brown with a golden or reddish cast). Sapwood colour distinct from heartwood colour (sapwood greyish white with more or less pinkish tinge). Density 0.42–0.55 g/cm³.

Vessels. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 66–138 µm. Average number of vessels/mm² 4–9. Average vessel element length 348–500 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9–14 µm. Vessel-ray pits with reduced borders or apparently simple, rounded or angular, of uniform size or type, of the same type in adjacent elements. Tyloses in vessels present.

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres of medium wall thickness. Average fibre length 651–1009 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres septate and non-septate. Septate fibres very infrequent.

Axial parenchyma. Axial parenchyma paratracheal. Paratracheal axial parenchyma vasicentric, or aliform. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4.

Rays. Rays 6–14 per tangential mm, exclusively uniseriate or multiseriate (also if only few) (uniseriate in A. giganteum, A. occidentale and A. spruceanum, frequently biseriate in other species). Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows (with inner cells typically square).

Secretory structures. Oil and mucilage cells absent. Intercellular canals absent.

Mineral inclusions. Crystals not observed. Silica present, as grains, in rays cells.

Physical and chemical tests. Heartwood not fluorescent. Water extract fluorescent; basically colourless to brown or shade of brown. Ethanol extract fluorescent. Colour of ethanol extract colourless to brown or shade of brown, or yellow or shade of yellow.

Illustrations. • Transverse section. Anacardium sp. • Tangential section. Anacardium sp. Anacardium occidentale. Predominatly bi-seriate rays. Predominantly uni-seriate rays. • Radial section. Anacardium sp. (biseriate rays). Inset: Silica particles in ray cells (crystals absent). • Radial section. Anacardium occidentale (uni-seriate 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.’.