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Nomenclature etc. MALVACEAE (TILIACEAE). Syn.: Heliocarpus popayannensis Hook & Arn. Trade and local names: apeyva, yvyra pire hu, tapika guasu (PY); amores secos (AR); moho (US); balsa pancho, llausa mora, yarisa (BO); majao (BZ). Not protected under CITES regulations.
Description based on 5 specimens. Tree. Geographic distribution: tropical South America, southern Brazil.
General. Heartwood basically white or grey and brown. Sapwood colour similar to heartwood colour. Density 0.3 g/cm³.
Vessels. Vessels present. Wood diffuse porous. Vessels in multiples, commonly in short (2–3 vessels) radial rows. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9–15 µm. Vessel-ray pits with distinct borders or with reduced borders or apparently simple, similar to intervessel pits or different from intervessel pits, rounded or angular.
Tracheids and fibres. Fibres very thin-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent.
Axial parenchyma. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse, or diffuse-in-aggregates. Paratracheal axial parenchyma scanty. Axial parenchyma as strands. Average number of cells per strand: (2–)3–5(–7). Unlignified parenchyma present. Non lignified parenchyma in broad bands or larger flecks, irregularly distributed.
Rays. Rays multiseriate, (1–)3–5(–6) cells wide. Rays of two distinct sizes. Height of large rays commonly over 1000 µm. 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 present. With some longitudinally fused rays.
Storied structures. Storied structure present, some rays storied, some not, axial parenchyma storied, vessel elements storied, fibres storied. Arrangement of tiers irregular. Rays locally irregularly storied.
Mineral inclusions. Crystals present, prismatic, located in ray cells and axial parenchyma cells. Crystal-containing ray cells upright and/or square and procumbent, upright and/or square ray cells chambered and not chambered. Crystal-containing axial parenchyma cells chambered and not chambered. Number of crystals per cell or chamber one and more than one. With some subdivided (2–4, up to 8 times) square and upright marginal ray cells. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; colour of water extract colourless to brown. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown. Chrome azurol-S test positive (only along the periphery of the reaction area, possibly as a consequence of fungal decay). Froth test positive (weakly). Splinter burns to full ash. Ash dark grey.
Illustrations. • Transverse section. specimen with (left) and without (right) amply developed unlignified parenchyma. • Tangential section. • Radial section. • Crystals. prismatic crystals in chambered ray cells (left) and non-chambered axial parenchyma cells (right).
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’.
