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Nomenclature etc. PROTEACEAE. Species included in the description: Roupala cordifolia H.B.K., R. dissimilis Pittier, R. montana Aubl. Trade and local names: Perlholz, Elfenholz (DE); carvalho brasileiro (BR); lacewood, elf wood (US);. Not protected under CITES regulations.
Tree. Geographic distribution: Mexico and Central America, Caribbean, tropical South America.
General. Heartwood basically brown. Sapwood colour distinct from heartwood colour. Density 0.85–0.95 g/cm³. With conspicuous silver grain (high rays).
Vessels. Wood diffuse porous. Vessels arranged in tangential bands, in multiples, commonly in clusters. Vessels also in tangentially oriented multiples of 2–4. Average tangential vessel diameter 120 µm. Average number of vessels/mm² (7–)9–12(–16). 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. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings absent. Other deposits 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.
Axial parenchyma. Axial parenchyma banded. Bands not marginal (or seemingly marginal). Axial parenchyma bands forming a scalariform pattern with rays. Bands fine. Axial parenchyma as strands. Average number of cells per strand: 3–5(–7).
Rays. Rays 1–3 per tangential mm, multiseriate, 10–30 cells wide. Rays of two distinct sizes. Height of large rays commonly over 1000 µm. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent. Sheath cells present and absent. Also with uniseriate rays composed solely of upright cells.
Mineral inclusions. Crystals not observed. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; colour of water extract colourless to brown. Ethanol extract fluorescent (weakly yellow). Colour of ethanol extract colourless to brown. Chrome azurol-S test positive. Splinter burns to full ash. Ash white to grey.
Illustrations. • Macroscopic images. transverse (ca. 10x). tangential (natural size). • Transverse section. Roupala sp. • Tangential section. Roupala sp. • Radial section. Roupala sp.
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: 9th April 2019. delta-intkey.com’.
