Commercial Timbers


H. G. Richter and M. J. Dallwitz

Juglans australis Griseb., Juglans spp. (Nogal, tropical walnut)

Nomenclature etc. JUGLANDACEAE. + J. boliviana Dode; J. jamaicensis C.DC. (Syn.: J. insularis Griseb.); J. neotropica Diels.; J. olanchana Standl. & Williams. Trade and local names: nogal (cAm, sAm), Tropischer Nussbaum (DE), tropical black walnut (GB, US). Not protected under CITES regulations.

Tree. Geographic distribution: Mexico and Central America and tropical South America.

General. Growth ring boundaries distinct. Heartwood basically brown red, with streaks. Sapwood colour distinct from heartwood colour. Density 0.55–0.7 g/cm³.

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 134–285 µm. Average number of vessels/mm² 11–18. Average vessel element length 515–812 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 11–13 µm. Vessel-ray pits with reduced borders or apparently simple, rounded or angular, of the same type in adjacent elements and unilaterally compound and coarse. Tyloses in vessels present, thinwalled. Other deposits in heartwood vessels not observed.

Tracheids and fibres. Fibres of medium wall thickness. Average fibre length 1042–1935 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered.

Axial parenchyma. Axial parenchyma present, banded. Axial parenchyma bands scalariform, fine, up to three cells wide. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4–8.

Rays. Rays 7–11 per tangential mm, multiseriate (also if only few), (1–)3 cells wide. Rays of two distinct sizes. 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.

Storied structures. Storied structure absent.

Secretory structures. Intercellular canals absent.

Cambial variants. Included phloem 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. Silica not observed.

Illustrations. • Transverse section. Juglans neotropica. • Tangential section. Juglans neotropica. • Radial section + crystals. All tropical Juglans species possess prismatic crystals in chambered axial parenchyma cells (right). Juglans neotropica.

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.’.