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Nomenclature etc. MALVACEAE (STERCULIACEAE). Syn.: Guazuma tomentosa H.B.K., G. polybotrya Cav., G. bubroma Tuss.,Theobroma guazuma L., T. foliis serratis L., Diuroglossum rufescens Turcz. Trade and local names: kamba akã (PY); imbiruçú, embirú, mutamba (BR); guácima, cuaulote, aquiché, kabal-pixoy, pixoy, acashti, ajillá, majagua de toro, nocuana-yana, palote negro, parandesiqua, tablote, tzuni, tzyui, uiguie, ya-ana, yaco granadillo, yaco de venado, zam-mi, áquich, ajya, k'olin kakaw (MX); guácimo blanco (VE); guásimo (PE); guásima (CU); bastard cedar, West Indian elm (US); bois d'orme (FR); vácima (ES); bolaina negra (PE). Not protected under CITES regulations.
Description based on 2 specimens. Tree. Geographic distribution: Mexico and Central America, Caribbean, tropical South America, southern Brazil.
General. Growth ring boundaries distinct. Demarcated by a nearly invisible (uniseriate) marginal parenchyma band, local thickening of rays, and thicker walled latewood fibres. Heartwood basically white or grey. Sapwood colour similar to heartwood colour. Density 0.48–0.65 g/cm³.
Vessels. Wood diffuse porous. Vessels in multiples, commonly in short (2–3 vessels) radial rows or in radial rows of 4 or more. Average tangential vessel diameter (60–)110–150(–170) µm. Average number of vessels/mm² 6–19. Average vessel element length 330–400 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 4–5 µm. Vessel-ray pits with distinct borders, similar to intervessel pits. Other deposits present (brown, rather scarce).
Tracheids and fibres. Fibres of medium wall thickness. Average fibre length 850–1940 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres non-septate.
Axial parenchyma. Axial parenchyma banded. Bands marginal (or seemingly marginal) (marginal bands hardly visible in transverse section due to the similarity (dimension and wall thickness) with fibres). Bands fine. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse, or diffuse-in-aggregates. Paratracheal axial parenchyma scanty and vasicentric. Axial parenchyma as strands. Average number of cells per strand: 3–8. The number of cells per strand differs for paratracheal (4–8) and apotracheal (3–5) axial parenchyma.
Rays. Rays 5–13 per tangential mm, multiseriate, (1–)2–5 cells wide. 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. Sheath cells absent. Tile cells present. Rays considered heterocellular as procumbent and tile cells are mixed.
Storied structures. Storied structure present, some rays storied, some not, axial parenchyma storied, vessel elements storied, fibres storied. Arrangement of tiers regular, or irregular. Number of ray tiers per axial millimetre 2. Only the low (small) rays are storied.
Secretory structures. Intercellular canals absent.
Mineral inclusions. Crystals present, prismatic, located in ray cells and axial parenchyma cells. Crystal-containing ray cells procumbent. Crystal-containing axial parenchyma cells chambered and not chambered. Number of crystals per cell or chamber one. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; colour of water extract colourless to brown to yellow. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown.
Illustrations. • Transverse section. • Tangential section. • Radial section. tile cells (blow-up lower left corner).
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’.
