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| Commercial timbers |
Nomenclature etc. EUPHORBIACEAE. Trade and local names: castanha de proco, mirindimba-doce, pau doce, pau-de-casca-doce (BR); devildoer (GY); saint Martin blanc, wandecolle (GF). Not protected under CITES regulations.
Description based on 3 specimens. Tree. Geographic distribution: tropical South America.
General. Growth ring boundaries distinct. Demarcated by several rows of radially flattened and thick-walled fibres (latewood). Heartwood basically orange brown (orange). Sapwood colour distinct from heartwood colour. Density 0.6 g/cm³.
Vessels. Wood diffuse porous. Vessels arranged in no specific pattern, in multiples, commonly in short (2–3 vessels) radial rows and in radial rows of 4 or more. Average tangential vessel diameter 55–105–140 µm. Average number of vessels/mm² (4–)7–8(–10). Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 11–12 µm. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings absent. Tyloses present, thinwalled.
Tracheids and fibres. Fibres of medium wall thickness. Fibre pits mainly restricted to radial walls, distinctly bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma banded or not banded. Axial parenchyma bands forming a reticulate pattern with rays. Bands fine (mostly very wavy). Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma scanty, or unilateral. Axial parenchyma as strands. Average number of cells per strand: 4–8.
Rays. Rays 5–7 per tangential mm, multiseriate, (1–)2–4 cells wide. Aggregate rays absent. Rays of two distinct sizes (depending on interpretation), or of one size. Height of large rays commonly 500 to 1000 µm. Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows, mostly 2–4 marginal rows of upright or square cells. Sheath cells absent.
Storied structures. Storied structure absent.
Secretory structures. Intercellular canals absent. Laticifers or tanniniferous tubes absent.
Cambial variants. Included phloem absent.
Mineral inclusions. Crystals present, prismatic, located in ray cells and axial parenchyma cells. Crystal-containing ray cells upright and/or square, upright and/or square ray cells chambered. Crystals in procumbent ray cells not in radial alignment. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one and more than one. Styloid crystals occasionally present. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; colour of water extract colourless to brown. Ethanol extract fluorescent (yellowish). Colour of ethanol extract colourless to brown. Froth test negative. Splinter burns to partial ash. Ash white to grey.
Illustrations. • Transverse section. • Tangential section. • Radial section. • Crystals. prismatic crystals of different sizes in chambered and non-chambered ray cells. prismatic crystals in chambered axial parenchyma cells.
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’.
