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Nomenclature etc. SALICACEAE. Populus alba L., P. canescens Sm., P. deltoides Marsh., P. grandidentata Michx., P. heterophylla L., P. nigra L., P. tremula L., P. tremuloides Michx. Trade and local names: Zitterpappel, Aspe, Espe, Silberpappel, Euphrat-Pappel, Schwarzpappel (DE); aspen, poplar, black poplar (GB); abeel espen, populieren (NL); peuplier, tremble (FR); titreh kavak (TR); pioppo tremolo (IT); álamo temblon (ES); topol cerny (CZ); topola crna (CS); plop negru (RO); fekete nyér (HU); aspen, cottonwood (CA, US). Not protected under CITES regulations.
Tree. Geographic distribution: Europe, excl. Mediterranean, Mediterranean incl. N. Africa and Middle East, temperate Asia, India, Pakistan, Sri Lanka, North America.
General. Growth ring boundaries distinct. Heartwood basically red (nur der fakultative Kern only facultative heartwood), yellow, white or grey. Sapwood colour similar to heartwood colour (occasionally also), or distinct from heartwood colour. Density 0.36–0.45–0.56 g/cm³.
Vessels. Wood diffuse porous. Vessels in multiples, commonly in short (2–3 vessels) radial rows. Average tangential vessel diameter 40–65–95 µm. Average number of vessels/mm² 25–45–70. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9–11 µm. Vessel-ray pits with reduced borders or apparently simple, different from intervessel pits, rounded or angular, restricted to marginal rows. Helical thickenings absent. Tyloses present (few), thinwalled.
Tracheids and fibres. Fibres very thin-walled. Average fibre length 220–1100–2100 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered.
Axial parenchyma. Axial parenchyma banded. Bands marginal (or seemingly marginal). Bands fine.
Rays. Rays 8–13 per tangential mm, exclusively uniseriate. Aggregate rays absent. Height of large rays up to 500 µm. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent.
Storied structures. Storied structure absent.
Secretory structures. Intercellular canals absent.
Mineral inclusions. Crystals not observed. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract fluorescent (weakly greenish blue in some specimens), or not fluorescent; colour of water extract colourless to brown. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown. Froth test positive (only discolored heartwood), or negative. Splinter burns to full ash, or to partial ash. Ash white to grey (nearly black).
Illustrations. • Macroscopic images. transverse (ca. 10x). radial (natural size). • Transverse section. Populus alba. • Tangential section. Populus alba. • Radial section. Populus alba. • Vessel-ray pits. Populus ciliata. vessel-ray pits restricted to marginal (contact) 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’.
