Description:

• Trees with furrowed, pale bark and terete or angled branches with terminal buds; winter buds resinous, with several unequal outer scales
• Leaves alternate, mostly broadly ovate to rhombic, long-stalked, entire or dentate; stipules membranous, small, narrow
• Inflorescences pendulous, odourless catkins, appearing before leaves
• Flowers unisexual, anemophilous; borne in axil of a serrate or laciniate bract; perianth reduced to a cup-like disc
• Male flowers with 4-30 or more stamens; filaments free; anthers 2-thecous, oblong to ovate, red
• Female flowers with ovary sessile or subsessile, 1-locular; ovules many; style very short, 2-4-branched, each branch entire or 2- or 3-fid
• Capsule 2-4-valved
• Seeds many, brown, small and ovoid or obovoid, with a tuft of long silky hairs arising from the funicle
• x = 19 (aneuploids, polyploidy)

Nomenclature:

• *Populus L.
  • Linnaeus: 1034 (1753)
  • Linnaeus: 456 (1754)
  • Adanson: 376 (1763)
  • Jussieu: 409 (1789)
  • Willdenow: 802 (1806)
  • Andersson: 323 (1868)
  • Bentham: 412 (1880)
  • Pax: 35 (1888)
  • Adamson: 311 (1950)
  • Bailey & Bailey: 900 (1976)
  • Wilmot-Dear: 121 (1991)

Distribution & Notes:

• Global: Species ± 40, confined to northern temperate and subtropical regions apart from the single East African species Populus ilicifolia (Engl.) Rouleau
• Southern Africa: A few species have been widely cultivated, e.g. P. deltoides Bartram ex Marshall (Match Poplar) principally for wood pulp, matches and boxes; 2 species have escaped and become naturalised, especially in marshy areas and in river valleys: *P. alba L. (White Poplar) and *P. X canescens (Aiton) Sm. (Grey Poplar), where they spread by suckering; the latter is now a widespread invader of watercourses in the Western Cape (Henderson 1998)