Commercial Timbers


H. G. Richter and M. J. Dallwitz

Lonchocarpus leucanthus Burk. (Yvyra ita)

Nomenclature etc. FABACEAE-FABOIDEAE. Syn.: Lonchocarpus albiflorus Hassk. Trade and local names: yvyra ita, rabo ita (PY); rabo de macaco (AR). Not protected under CITES regulations.

Tree. Geographic distribution: southern Brazil and temperate South America.

General. Growth ring boundaries distinct. Growth ring boundaries demarcated by marginal parenchyma bands accompanied by a dark band of fibres (latewood) almost void of parenchyma. Heartwood basically brown to yellow, with streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Density 0.9 g/cm³.

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows or radial rows of 4 or more. Vessel outline rounded. Two distinct vessel diameter classes absent. Average tangential vessel diameter 173 µm; diameter of vessel lumina: large. Average number of vessels/mm² 1; vessels per square millimetre very few. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9–12 µm, large, 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 absent. Other deposits in heartwood vessels not observed, tyloses observed in only one specimen - probably of traumatic origin; yellow to amber organic contents frequent.

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) and not marginal (or seemingly marginal), bands much wider than rays, fine, up to three cells wide to coarse, more than three cells wide. Marginal bands very fine, other bands usually wider (3 and more cells); marginal bands discontinuous in some specimens. Axial parenchyma apotracheal. Paratracheal axial parenchyma aliform to confluent. Aliform parenchyma lozenge. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4. Unlignified parenchyma absent. Short bands and parenchyma islands mostly not in contact with vessels.

Rays. Rays present, multiseriate (also if only few), 2–4 cells wide, narrow (2–3 seriate) to 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 up to 500 µm. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent. Sheath cells absent. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent.

Storied structures. Storied structure present, all rays storied, axial parenchyma storied, vessel elements storied, fibres storied or not storied. Arrangement of tiers regular (horizontal or straight). Number of ray tiers per axial millimetre 3–4. Storeying of rays sometimes irregular.

Secretory structures. Oil and mucilage cells absent. Intercellular canals absent. Laticifers or tanniniferous tubes 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. Crystal containing cells of normal size. Cystoliths absent. Crystals in marginal parenchyma numerous; several crystals of the same size in a single parenchyma cell less frequent; crystals also observed in (traumatic) tyloses. Silica not observed.

Illustrations. • Transverse section. Lonchocarpus leucanthus. • Tangential section. Lonchocarpus leucanthus. • Radial section. Lonchocarpus leucanthus.

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.’.