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) cottonwood (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, and North America.
General. Growth ring boundaries distinct. Heartwood basically yellow to white or grey. Sapwood colour similar to heartwood colour, or distinct from heartwood colour. Density 0.36–0.45–0.56 g/cm³.
Vessels. Wood diffuse-porous. Vessels in multiples, commonly 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) 10–11 µm. Vessel-ray pits with reduced borders or apparently simple, rounded or angular, restricted to marginal rows. Helical thickenings absent. Tyloses in vessels 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. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide.
Rays. Rays 8–13 per tangential mm, exclusively uniseriate. Aggregate rays absent. 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. Splinter burns to full ash, or to partial ash. Ash white to grey, or other than white, grey, yellow or brown (nearly black).
Illustrations. • Transverse section. Populus alba. • Tangential section. Populus alba. • Radial section. Populus alba. • Ray-vessel crossfield. Populus ciliata. Ray-vessel pitting 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: 25th June 2009. http://delta-intkey.com’.