Roupala spp. ()
Nomenclature etc. PROTEACEAE. Species included in the description: Roupala cordifolia H.B.K., R. dissimilis Pittier, R. montana Aubl.
Geographic distribution: tropical South America.
General. Growth ring boundaries indistinct or absent. Heartwood basically brown, without streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. With conspicuous silver grain (high rays).
Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in tangential bands and no specific pattern, in multiples, commonly in clusters. Vessel outline rounded. Two distinct vessel diameter classes absent. Vessels also in tangentially oriented multiples of 2–4. Average tangential vessel diameter 120 µm. Average tangential diameter of vessel lumina large. Average number of vessels/mm² (7–)9–12(–16). Vessels per square millimetre few. R. cordifolia: mean vesel diameter 55 µm, up to 40 vessels per mm². Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 3–5 µm, minute and 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 absent. Other deposits in heartwood vessels present and not observed, brown deposits in R dissimilis.
Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres very thick-walled. 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 not marginal (or seemingly marginal), scalariform, fine, up to three cells wide. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 3–5(–7). Unlignified parenchyma absent.
Rays. Rays present, 1–3 per tangential mm, multiseriate, also if only few, 10–30 cells wide, commonly more than 10 cells wide. Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays of two distinct sizes. Height of large rays commonly over 1000 µm. Rays composed of a single cell type. Homocellular ray cells procumbent. Sheath cells present and absent. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent. Also with uniseriate rays composed solely of upright cells.
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 not observed. Cystoliths absent. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent. Water extract basically colourless to brown or shade of brown. Heartwood extractives not leachable by water. Ethanol extract fluorescent (weakly yellow). Ethanol extract basically colourless to brown or shade of brown. Chrome azurol-S test positive. Froth test negative. Splinter burns to full ash. Ash white to grey.
Cite this publication as: H. G. Richter and M. J. Dallwitz (2000 onwards). 'Commercial timbers: descriptions, illustrations, identification, and information retrieval.' In English, French, German, and Spanish. Version: 4th May 2000. http://biodiversity.uno.edu/delta/.
Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993 onwards, 1995 onwards, 1998) should also be cited (see General references).