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Nomenclature etc. FABACEAE-FABOIDEAE. Syn.: Torresea cearensis Fr. Allem. Trade and local names: amburana, cumarú de cheiro, imburana, umburana (BR); ishpingo (PE); sorioco, roble americano (BO); roble criollo, roble del país, roble, palo trébol, trébol (AR); trébol (PY). Not protected under CITES regulations.
Description based on 6 specimens. Tree. Geographic distribution: tropical South America, southern Brazil, temperate South America.
General. Growth ring boundaries distinct or indistinct or absent. Heartwood basically yellow to brown; with streaks (occasionally with darker (latewood) striping) or without streaks. Sapwood colour distinct from heartwood colour. Odour distinct (sweetish = cumarin). Density 0.52–0.57–0.65 g/cm³.
Vessels. Wood diffuse porous. Vessels in multiples, commonly in short (2–3 vessels) radial rows. Average tangential vessel diameter 145–195–230 µm. Average number of vessels/mm² 2–6. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 5–7 µm, pits vestured. Vessel-ray pits with distinct borders, similar to intervessel pits, of uniform size or type. Helical thickenings absent. Other deposits present (dark yellowish or greenish brown).
Tracheids and fibres. Fibres of medium wall thickness. Average fibre length 700–1000 µm. Fibre pits common in both radial and tangential walls, simple to minutely bordered.
Axial parenchyma. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma aliform and confluent (towards growth ring boundary distinctly confluent or forming irregular bands). Aliform parenchyma of the lozenge type. Axial parenchyma as strands. Average number of cells per strand: 2–4(–6).
Rays. Rays 4–6(–7) per tangential mm, multiseriate, (1–)2–3(–4) cells wide. Height of large rays up to 500 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.
Storied structures. Storied structure present or absent, all rays storied, axial parenchyma storied, vessel elements storied. Arrangement of tiers irregular. Storeying of rays and axial parenchyma often irregular or incomplete.
Mineral inclusions. Crystals present, prismatic, located in ray cells and axial parenchyma cells. Crystal-containing ray cells upright and/or square and procumbent. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Silica not observed.
Physical and chemical tests. Heartwood fluorescent. Water extract not fluorescent; colour of water extract colourless to brown. Ethanol extract not fluorescent. Colour of ethanol extract yellow. Froth test positive. Splinter burns to partial ash. Ash white to grey.
Illustrations. • Macroscopic images. transverse (ca. 10x). tangential (natural size). • Transverse section: Axial parenchyma normal. paratracheal parenchyma "normally" developed. • Transverse section: Axial parenchyma abundant. paratracheal parenchyma abundant. • Tangential section. • Radial section. prismatic crystals in both axial and ray parenchyma cells (Cr). Cr». Cr».
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’.
