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Nomenclature etc. LAURACEAE. Description based on approximately 30 species from tropical Asia and the australo-pacific region. Trade and local names: medang (trade); cryptocarya (PG); dugkatan, manayau (PH). Not protected under CITES regulations.
Description based on 40 specimens. Tree. Geographic distribution: Indomalesia, Pacific Islands, Australia (further species are native to Madagascar and southern South America).
General. Growth ring boundaries distinct or indistinct or absent (demarcated by marginal parenchyma bands, not in all instances distinct). Heartwood basically brown, white or grey. Sapwood colour similar to heartwood colour, or distinct from heartwood colour. Odour distinct, or indistinct or absent. Density 0.55–0.77 g/cm³.
Vessels. Vessels present. Wood diffuse porous. Vessels arranged in no specific pattern, in multiples, commonly in short (2–3 vessels) radial rows or in radial rows of 4 or more. Average tangential vessel diameter 60–170(–230) µm. Average number of vessels/mm² (5–)9–12. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) (8–)10–14 µm. Vessel-ray pits with reduced borders or apparently simple, different from intervessel pits, rounded or angular and horizontal to vertical. Tyloses present, thinwalled and sclerotic. Tyloses partly sclerotic in C.nitens.
Tracheids and fibres. Fibres of medium wall thickness. Average fibre length (700–)1000–1400(–1600) µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma banded. Bands marginal (or seemingly marginal). Bands fine and coarse. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma vasicentric. Axial parenchyma as strands. Average number of cells per strand: 2–4(–8).
Rays. Rays 5–8 per tangential mm, multiseriate, (1–)2–4(–6) cells wide. Aggregate rays present (in C. chinensis, C. corrugata, C. glaucescens, C. meissneri), or absent. Rays of two distinct sizes, or of one size. Height of large rays up to 500 µm and 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 1 marginal row of upright or square cells or mostly 2–4 marginal rows of upright or square cells.
Storied structures. Storied structure absent.
Secretory structures. Oil and mucilage cells present, associated with axial parenchyma and ray parenchyma (in rays only sporadically). Laticifers or tanniniferous tubes absent.
Mineral inclusions. Crystals present and not observed, in other forms, located in ray cells. Crystal-containing ray cells upright and/or square and procumbent. Number of crystals per cell or chamber more than one. Crystals usually small (isodiametric, rod-like, acicular) and observed in: C. crassinervia, C. ferrea, C. membranaceae, C. multipaniculata, C. nitens, C. tomentosa, C. triplinervis, C. vulgaris. Silica present or not observed, as grains and in aggregates; in rays cells. Silica observed in: C. aristata, C. corrugata, C. gigantocarpa, C. glaucescens, C. invasorium, C. leptospermoides, C. odorata, C. pluricostata, C. transversa..
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. Froth test positive. Splinter burns to partial ash. Ash yellow-brown.
Illustrations. • Transverse section. Cryptocarya cunninghamii: vessels mostly solitary. Cryptocarya densiflora: vessels mostly in radial groups. • Transverse section enlarged. Cryprocarya ferrea: marginal bands and paratracheal parenchyma, numerous oil cells. • Tangential section. Cryptocarya ferrea. • Radial section. Cryptocarya oblata. • Intervessel pitting; fibre pits. Cryptocarya massoy: large alternate intervessel pitting. Cryptocarya odorata: numerous prominent fibre pits in radial walls. • Oil cells. Cryptocarya pluricostata: numerous large oil cells associated with axial parenchyma and/or fibres. radial. tangential. Cryptocarya oblata: oil cells associated with axial parenchyma and rarely with rays. radial. • Mineral inclusions. Cryptocarya mackinnoniana: numerous small crystals in ray cells (semi-polarized light). Cryptocarya leptospermoides: irregular silica particles in ray 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’.
