Commercial Timbers

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H. G. Richter and M. J. Dallwitz

Glycydendron amazonicum Ducke (Glícia)

Nomenclature etc. EUPHORBIACEAE. Trade and local names: mirindiba-doce, pau-de-casca-doce (BR). Not protected under CITES regulations.

Description based on 3 ((specimens)). Tree. Geographic distribution: tropical South America.

General. Growth ring boundaries distinct. Growth ring limits demarcated by several rows of radially flattened and thick-walled fibres (latewood).. Heartwood basically orange brown (-orange), without streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Wood of commercial potential.

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows and radial rows of 4 or more. Vessel outline rounded. Two distinct vessel diameter classes absent. Average tangential vessel diameter 55–105–140 µm; diameter of vessel lumina: medium and large. Average number of vessels/mm² (4–)7–8(–10); vessels per square millimetre few. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 11–12 µm, large, not vestured. Vessel-ray pits with distinct borders, similar to intervessel pits, of uniform size or type, of the same type in adjacent elements, located throughout the ray. Helical thickenings absent. Tyloses in vessels present, thinwalled. Other deposits in heartwood vessels not observed.

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres of medium wall thickness. Fibre pits mainly restricted to radial walls, distinctly bordered. Helical thickenings absent. Fibres non-septate.

Axial parenchyma. Axial parenchyma present, banded. Axial parenchyma bands not marginal (or seemingly marginal), reticulate, fine, up to three cells wide. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma confluent and unilateral. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4–8. Unlignified parenchyma absent.

Rays. Rays present, 5–7 per tangential mm, multiseriate (also if only few), (1–)2–3 cells wide, narrow (2–3 seriate). Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays 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. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent.

Storied structures. Storied structure absent.

Secretory structures. Oil and mucilage cells absent. Intercellular canals absent.

Cambial variants. Included phloem absent. Other cambial variants 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. Crystals in one cell or chamber of the same size. Crystal containing cells of normal size. Cystoliths absent. Styloid crystals occasionally present. Silica not observed.

Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; basically colourless to brown or shade of brown. Heartwood extractives not leachable by water. Ethanol extract fluorescent ((yellowish)). Colour of ethanol extract colourless to brown or shade of brown. Chrome azurol-S test negative. Froth test negative. Splinter burns to partial ash. Ash white to grey.

Illustrations. • Transverse section. Glycydendron amazonicum. • Tangential section. Glycydendron amazonicum. • Radial section. Glycidendron amazonicum. • Crystals in rays and axial aprenchyma. Glycydendron amazonicum. 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: 25th June 2009. http://delta-intkey.com’.

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