Commercial Timbers


H. G. Richter and M. J. Dallwitz

Cordia glabrata (Mart.) A.DC. (Louro preto, piquana negra)

Nomenclature etc. BORAGINACEAE. Syn.: Gerascanthus glabrata Mart., Lithocardium glabratum Kuntze. Trade and local names: louro preto (BR), piquana negra, japunaqui (BO). Not protected under CITES regulations.

Description based on 9 specimens. Tree. Geographic distribution: tropical South America, southern Brazil, and temperate South America.

General. Growth ring boundaries distinct. Growth ring boundaries demarcated by marginal parenchyma bands (often discontinuous). Heartwood basically brown, with streaks. Sapwood colour distinct from heartwood colour. Density 0.8 g/cm³.

Vessels. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows and in clusters. Vessel outline rounded. Two distinct vessel diameter classes absent. Average tangential vessel diameter 60–110–140 µm; diameter of vessel lumina: large. Average number of vessels/mm² 7; vessels per square millimetre few. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 5–6 µm, small, not vestured. Vessel-ray pits with distinct borders, similar to intervessel pits, of uniform size or type, of the same type in adjacent elements, located throughout the ray. Helical thickenings absent. Tyloses in vessels present, thinwalled. Other deposits in heartwood vessels present, yellowish brown organic contents.

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

Axial parenchyma. Axial parenchyma present, banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide. Bands quite infrequent, apparently marginal. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma vasicentric and confluent. Axial parenchyma as strands. Average number of cells per axial parenchyma strand (2–)3–5. Unlignified parenchyma absent. Few fusiform parenchyma cells present.

Rays. Rays present, multiseriate (also if only few), (2–)4–6 cells wide, of medium width (3–5 seriate). Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays of one size. Height of large rays commonly 500 to 1000 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 and mostly 2–4 marginal rows of upright or square cells. Sheath cells present. 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 ray cells and axial parenchyma cells. Crystal-containing ray cells upright and/or square, upright and/or square ray cells not chambered. Crystal-containing axial parenchyma cells not chambered. Number of crystals per cell or chamber one and more than one. Crystals in one cell or chamber of the same size and of two distinct sizes. Crystal containing cells of normal size. Cystoliths absent. Silica present, as grains, in rays cells and in axial parenchyma. Crystals and silica occur frequently in one and the same cell.

Illustrations. • Macro images. Cordia glabrata. Transverse. Radial. • Transverse section. Cordia glabrata. • Tangential section. Cordia glabrata. • Radial section. Cordia glabrata. • Silica in rays and axial parenchyma. Cordia glabrata. Note: Silica particles in bothe ray and axial parenchyma cells. • Silica + crystals in rays. Cordia glabrata. Note: Silica and prismatic crystals occasionally present in one and the same ray cell, a rare coincidence.

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.’.