Pleiariana N. Chao & G. T. Gong

Trees or shrubs deciduous, rarely evergreen (if shrubs, then erect, ascending procumbent, creeping, or cushion-shaped); pith terete. Branches terete. Terminal bud usually absent; buds with single scale. Leaves alternate, rarely subopposite or opposite; stipules small, free, deciduous or persistent, developed mainly on vigorous branchlets; petiole short; leaf blade variously shaped, often long and narrow. Flowering precocious, coetaneous, or serotinous; catkins upright or spreading, rarely pendulous; bracts entire, persistent or caducous. Flowers entomophilous or anemophilous, each with 1 or 2 glands: 1 abaxial (dorsal) or absent and 1 adaxial (ventral), i.e., abaxial gland between bract and stipe, adaxial gland between stipe and rachis. Male flower: stamens 2-many; filaments free or partly to completely connate, usually exceeding bracts; anthers 2-loculed (rarely 4-loculed if filaments connate), opening lengthwise. Female flower: ovary 2-loculed, sessile or stipitate; style 1, short, slender, or absent, entire or 2-cleft; stigmas 1 or 2, lobed or entire. Capsule 2-valved. Seeds mostly green or gray-green, small, surrounded by fine hairs.

About 520 species: cold and temperate regions of N hemisphere, a few in S hemisphere; 275 species (189 endemic, at least one introduced) in China.

A. K. Skvortsov indicates that sections Caesiae, Flavidae, Haoanae, and Helix are in many ways interrelated and might, therefore, be united. Salix hainanica A. K. Skvortsov (Harvard Papers in Botany 3: 107. 1998), was published just after this account was finalized, and it should be referred to sect. Tetraspermae. The genus Pleiarina, to which several taxa of Salix were transferred by N. Chao and G. T. Gong (J. Sichuan Forest. Sci. Tech. 17(2): 1-8. 1996), is here treated as a synonym of Salix.