Commercial Timbers


H. G. Richter and M. J. Dallwitz

Eperua spp. (Wallaba)

Nomenclature etc. FABACEAE-CAESALPINIOIDEAE. Species included in the description: Eperua falcata Aubl., E. jenmani Oliv. Trade and local names: espadeira, copaiba-rana, muirapiranga (BR); wallaba, yoboko (GY); bois de sabre, eperu, wapa (GF); roode walaba, bijlhout, tamoene (SR). Not protected under CITES regulations.

Description based on 10 specimens. Tree. Geographic distribution: tropical South America.

General. Growth ring boundaries indistinct or absent. Heartwood basically red, with streaks. Odour distinct. Density 0.75–0.95 g/cm³. Wood of commercial potential.

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows. Vessel outline rounded. Two distinct vessel diameter classes absent. Average tangential vessel diameter 100–190–310 µm; diameter of vessel lumina: large. Average number of vessels/mm² 3–5–7; vessels per square millimetre very few and few. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 4–7 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 (reddish brown).

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 not marginal (or seemingly marginal), bands much wider than rays, coarse, more than three cells wide. Axial parenchyma paratracheal. Paratracheal axial parenchyma vasicentric and confluent. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 3–4. Unlignified parenchyma absent.

Rays. Rays present, multiseriate (also if only few), (1–)2–4 cells wide, narrow (2–3 seriate). Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays of one size. 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 absent. 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 present, non-traumatic origin, axial type, in long tangential lines. Laticifers or tanniniferous tubes absent.

Cambial variants. Included phloem absent. Other cambial variants 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. Silica not observed.

Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; basically colourless to brown or shade of brown. Heartwood extractives not leachable by water. Ethanol extract fluorescent (orange). Colour of ethanol extract red or shade of red. Chrome azurol-S test negative. Froth test negative. Splinter burns to partial ash. Ash white to grey.

Illustrations. • Transverse section. Eperua falcata. • Tangential section. Eperua falcata. Note variation in size of individual ray cells represented by two different specimens (left and right) of the same species. • Radial section. Eperua falcata. V = Vessel; AC = Axial canal. AC. V. • Miscellaneous. Eperua falcata. Blow-up of vessel (V) with adjacent axial canals (AC). Axial parenchyma - chambered crystalliferous strands quite frequent (semi-polarized light). V. AC. AC.

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.’.