Nomenclature etc. FABACEAE-MIMOSOIDEAE. Trade and local names: yvyraro (PY); viraro, tipa colorada, tipa, tipila, palo mortero, cocal, ibiraro, palo rosa, palo coca (AR); amendoim, amendoim bravo, viraro (BR). Not protected under CITES regulations.
Description based on 6 specimens. Tree. Geographic distribution: southern Brazil and temperate South America.
General. Growth ring boundaries distinct. Growth ring boundaries demarcated by 2–3-seriate, sometimes discontinuous marginal parenchyma bands and slightly thickened (noded) rays. Heartwood basically brown and red, without streaks. Sapwood colour distinct from heartwood colour. Odour distinct (weakly so). Density 0.77 g/cm³.
Vessels. Vessels present. 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 120–160 µm; diameter of vessel lumina: large. Vessels per square millimetre very few and few. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 5–7 µm, small, 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 present, brown to black organic deposits.
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 and not banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide. Axial parenchyma paratracheal. Paratracheal axial parenchyma vasicentric and confluent. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4. Unlignified parenchyma absent. Parenchyma strands in contact with vessels mostly 4-seriate.
Rays. Rays present, 7–10 per tangential mm, multiseriate (also if only few), 2–3 cells wide, narrow (2–3 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. Arrangement of tiers regular (horizontal or straight). Number of ray tiers per axial millimetre 3–4.
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 procumbent. Crystals in procumbent ray cells not in radial alignment. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Crystal containing cells of normal size. Cystoliths absent. Crystals abundant in septate and non-septate marginal ray cells. Silica not observed.
Physical and chemical tests. Heartwood fluorescent (yellow fluorescence, sometimes in stripes). Water extract not fluorescent; basically colourless to brown or shade of brown. Heartwood extractives not leachable by water. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown or shade of brown. Chrome azurol-S test negative. Froth test negative. Splinter burns to charcoal.
Illustrations. • Transverse section. Pterogyne nitens. • Tangential section. Pterogyne nitens. • Radial section. Pterogyne nitens.
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. http://delta-intkey.com’.