Commercial Timbers


H. G. Richter and M. J. Dallwitz

Hieronyma alchorneoides Fr. Allem. (Pilón)

Nomenclature etc. EUPHORBIACEAE. + Hieronyma chocoensis Cuatr., H. laxiflora (Tul.) Muell.Arg., H. oblonga Muell.Arg., H. poasana Standl. Trade and local names: llorón colorado (CR); quindu cacao, carne asada (VE), mascarey (EC); pilón (trade, cAm); suradan, suradanni (SR, GY). Not protected under CITES regulations.

Description based on 10 specimens. Tree. Geographic distribution: Caribbean, or Mexico and Central America to tropical South America.

General. Heartwood basically brown red (light reddish brown, to chocolate brown, to dark red). Sapwood colour similar to heartwood colour, or distinct from heartwood colour (sapwood pinkish). Density 0.52–0.7 g/cm³.

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, exclusively solitary. Average tangential vessel diameter (120–)200–300 µm. Average number of vessels/mm² 4–7. Average vessel element length 590–1220–1730 µm. Perforation plates simple. Intervessel pits opposite or alternate, average diameter (vertical) 6–10 µm. Intervascular pitting extremely rare. Vessel-ray pits with reduced borders or apparently simple, rounded or angular or horizontal to vertical, of the same type in adjacent elements or unilaterally compound and coarse. Tyloses in vessels present, thinwalled. Other deposits in heartwood vessels present (reddish brown).

Tracheids and fibres. Vascular or vasicentric tracheids commonly present (vasicentric). Fibres of medium wall thickness. Average fibre length 1700–3480 µm. Fibre pits common in both radial and tangential walls, distinctly bordered. Fibres non-septate. Some fibres appear to have cross walls which, however, cannot safely be interpreted as septa (possibly organic contents); septa were therefore coded as absent.

Axial parenchyma. Axial parenchyma apotracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 3–8.

Rays. Rays 6–10 per tangential mm, multiseriate (also if only few), 3–7 cells wide (only large rays). Rays of two distinct sizes. Height of large rays commonly over 1000 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 or with more than 4 marginal rows of upright or square cells.

Secretory structures. Intercellular canals absent.

Mineral inclusions. Crystals present, prismatic, located in ray cells or axial parenchyma cells. Crystal-containing ray cells upright and/or square or procumbent, upright and/or square ray cells chambered or not chambered. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Crystal containing cells of normal size. Silica not observed.

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

Illustrations. • Transverse section. Hieronyma alchorneoides. • Tangential section. Hieronyma alchorneoides. • Radial section. Hieronyma alchorneoides.

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.’.