Rhamnus frangula L. (Faulbaum)
Nomenclature etc. RHAMNACEAE. Status of protection under CITES regulations: not protected.
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 darke bands of radially flattened fibres (latewood). Heartwood basically brown, without streaks. Sapwood colour distinct from heartwood colour. Basic specific gravity 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. Average tangential 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, 2–3 cells wide. 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 rays square and upright cells restricted to marginal rows. Number of marginal rows of upright or square cells 1. 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. Water extract basically yellow or shade of yellow. Heartwood extractives not leachable by water. Ethanol extract fluorescent. Ethanol extract basically colourless to brown or shade of brown. Chrome azurol-S test negative. Froth test negative. Splinter burns to partial ash. Ash white to grey.
Cite this publication as: H. G. Richter and M. J. Dallwitz (2000 onwards). 'Commercial timbers: descriptions, illustrations, identification, and information retrieval.' In English, French, German, and Spanish. Version: 4th May 2000. http://biodiversity.uno.edu/delta/.
Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993 onwards, 1995 onwards, 1998) should also be cited (see General references).