Commercial Timbers


H. G. Richter and M. J. Dallwitz

Aspidosperma polyneuron Muell. Arg. (Peroba rosa)

Nomenclature etc. APOCYNACEAE. Syn.: Aspidosperma peroba Fr. All. Trade and local names: palo rosa, yvyraro mi, peroba (PY); palo rosa (AR); peroba, perova, peroba rosa, peroba amargosa, peroba-rajada, peroba-açu, sobro, peroba comum, peroba-do-rio, peroba-paulista, peroba-mirim, peroba-miúda (BR). Not protected under CITES regulations.

Description based on 4 specimens. Tree. Geographic distribution: southern Brazil.

General. Growth ring boundaries distinct and indistinct or absent. Growth ring boundaries, if microscopically distinct, demarcated by zones of smaller, thicker walled and radially flattened fibres in combination with fewer and smaller vessels. Heartwood basically red. Odour indistinct or absent. Density 0.75–0.85 g/cm³.

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, exclusively solitary. Vessel outline rounded. Two distinct vessel diameter classes absent. Average tangential vessel diameter 20–90 µm; diameter of vessel lumina: small and medium. Average number of vessels/mm² 50–80; vessels per square millimetre numerous. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 3–5 µm, minute, 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. Ray-vessel pits appear largely restricted to marginal cell rows; however, this character does not apply to all specimens. Helical thickenings absent. Tyloses in vessels present, thinwalled. Other deposits in heartwood vessels present, amber coloured organic contents rare.

Tracheids and fibres. Vascular or vasicentric tracheids commonly present. Fibres of medium wall thickness to very thick-walled. Average fibre length 700–1000–1250 µm. Average fibre length medium. Fibre pits common in both radial and tangential walls, distinctly bordered. Helical thickenings absent. Fibres non-septate.

Axial parenchyma. Axial parenchyma present, not banded. Axial parenchyma apotracheal. Apotracheal axial parenchyma diffuse and diffuse-in-aggregates. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4(–6). Unlignified parenchyma absent.

Rays. Rays present, 7–9 per tangential mm, multiseriate (also if only few), (1–)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. Predominantly biseriates.

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 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. Crystals in rays rare. Silica not observed.

Physical and chemical tests. Heartwood not fluorescent. Water extract fluorescent; basically colourless to brown or shade of brown. Heartwood extractives not leachable by water. Ethanol extract fluorescent (blueish white). Colour of ethanol extract colourless to brown or shade of brown. Chrome azurol-S test negative. Froth test positive (weakly légèrement). Splinter burns to charcoal.

Illustrations. • Transverse section. Aspidosperma polyneuron. • Tangential section. Aspidosperma ployneuron. • Radial section. Aspidosperma polyneuron. • Miscellaneous. Aspidosperma polyneuron. Prismatic crystals in chambered axial parenchyma cells (semi-polarized light); note large bordered fibre pits .

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.’.