Commercial Timbers

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H. G. Richter and M. J. Dallwitz

Rhamnus frangula L. (Faulbaum, alder buckthorn)

Nomenclature etc. RHAMNACEAE. Not protected under CITES regulations.

Description based on 3 specimens. Tree. Geographic distribution: Europe, excl. Mediterranean, Mediterranean incl. N. Africa and Middle East, and temperate Asia.

General. Growth ring boundaries distinct. Growthring limits marked by darker bands of radially flattened fibres (latewood). Heartwood basically brown, without streaks. Sapwood colour distinct from heartwood colour. Density 0.55–0.6 g/cm³.

Vessels. Vessels present. Wood semi-ring-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. Outline of vessels sometimes irregular. Average tangential vessel diameter 30–40–65 µm; diameter of vessel lumina: medium. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9–11 µm, medium and large, not vestured. Vessel-ray pits with distinct borders and with reduced borders or apparently simple, similar to intervessel pits, rounded or angular, of uniform size or type, of the same type in adjacent elements, located throughout the ray. Helical thickenings present, in narrow and wide vessel elements, throughout the body of vessel elements. Tyloses in vessels present, thinwalled. Other deposits in heartwood vessels present, brown.

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres very thin-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres non-septate.

Axial parenchyma. Axial parenchyma present, not banded. Axial parenchyma paratracheal. Paratracheal axial parenchyma scanty. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 6–8. Unlignified parenchyma absent.

Rays. Rays present, 5–8 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 up to 500 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 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. Silica not observed.

Physical and chemical tests. Heartwood not fluorescent. Water extract fluorescent; basically yellow or shade of yellow. Heartwood extractives not leachable by water. Ethanol extract fluorescent. 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. Rhamnus frangula. • Tangential section. Rhamnus frangula. • Radial section. Rhamnus frangula.


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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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