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| Commercial timbers |
Nomenclature etc. RHAMNACEAE. Not protected under CITES regulations.
Description based on 4 specimens. Tree. Geographic distribution: Europe, excl. Mediterranean.
General. Growth ring boundaries distinct. Demarcated by radially flattened fibres (latewood) and a continuous band of earlywood pores. Heartwood basically brown, red, and yellow. Sapwood colour distinct from heartwood colour.
Vessels. Vessels present. Wood semi ring porous and diffuse porous. Vessels arranged in a dendritic pattern, in multiples, commonly in clusters. Almost no solitary vessels. Average tangential vessel diameter 25–38–50 µm; diameter of vessels: small. Average number of vessels/mm² 100–330; vessels per square millimetre very numerous. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 6–8 µm, average diameter (vertical) small and medium, pits not vestured. Vessel-ray pits with distinct borders, different from intervessel pits, of uniform size or type, of the same type in adjacent elements, located throughout the ray. Vessel-ray pits are smaller than intervascular pits. Helical thickenings present, in narrow and wide vessel elements, throughout the body of vessel elements. Tyloses absent. Other deposits present, deposits yellow-brown.
Tracheids and fibres. Vascular or vasicentric tracheids commonly present. Fibres very thin-walled and of medium wall thickness. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres non-septate. Tracheids with helical thickenings within groups of vessels.
Axial parenchyma. Axial parenchyma absent or extremely rare. Paratracheal axial parenchyma scanty. Axial parenchyma as strands. Average number of cells per strand: 2–4.
Rays. Rays present, 10–13 per tangential mm, multiseriate, 1–3 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 up to 500 µm. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent. 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. Laticifers or tanniniferous tubes absent.
Cambial variants. Included phloem absent. Other cambial variants absent.
Mineral inclusions. Crystals not observed. Cystoliths absent. Silica not observed.
Physical and chemical tests. Heartwood fluorescent. Water extract fluorescent; colour of water extract colourless to brown. Heartwood extractives leachable when in contact with water (little). Ethanol extract fluorescent. Colour of ethanol extract colourless to brown. Chrome azurol-S test negative. Froth test negative. Splinter burns to partial ash. Ash white to grey.
Illustrations. • Transverse section. • Tangential section. • Radial section.
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’.
