10. Salix caesia Vill., Hist. Pl. Dauphiné. 3: 768. t. 50 f. 11. 1789; Nazarov in Kom., Fl. USSR 5: 177. 1936; Rech.f. in Tutin et al., Fl. Europ. 1: 46. 1964; A.K. Skvortsov in Rech.f., Fl. Iran. 65: 36. 1969; R.R. Stewart, Ann. Cat. Vasc. Pl. W. Pak. Kashm. 182. 1972; F. Zhenfu, Z.Shidong & A.K. Skvortsov l.c. 262.
S. divergens Andersson in DC., Prodr. 16(2): 316. 1868; Hook.f., Fl. Brit. Ind. 5: 637. 1888; S. myricaefolia Andersson in Kung. Svenska Vet.-Akad. Handl. 1850: 483. 1851; R. Parker, For. Fl. Punj. ed. 3: 510. 1956.
Dwarf shrub, young branches reddish-brown or reddish black, sometimes covered with silky hairs, becoming glabrous, stipules membranous, caducous. Petiole 1-3 mm long. Lamina 0.5-3 x 0.3-1 cm, oblong, elliptic or lanceolate, base cuncate or rotund or cordate, margin entire, tip obtuse to acute or mucronate, greyish green glabrous on both sides or dull with appressed hairs. Catkin ± serotinous with scale leaves at the base. Male (0.5)-1-2 cm long, sessile, stamens 2, filaments partly or completely united, densely hairy towards the base; gland 1, entire or 2-3 lobed. Female catkin 1-2 cm long; bract c. 1.5 mm long, brown; gland 1; ovary sessile to subsessile, c. 2-2.5 mm long; covered by dense silky hairs, style c. 0.5 mm or less long; branched with entire or bilobed stigmas at the tip. Capsule sessile to subsessile, 4-5 mm long, brown, hairy.
Fl. Per.: May.
Isotype: "Sur le Lautaret, le long des ruisseaux" (LE) A.K. Skvortsov (l.c. 36. 1969).
Distribution: Pakistan (Chitral, Gilgit), Kashmir, Afghanistan, Kirghizstan, China (Xinjiang, Xizang), Mongolia, Russia (S. Siberia), Europe (F. Zhenfu, Z. Shidong & A.K. Skvortsov l.c.).
Salix caesia resembles S. sclerophylla, however the two differ from each otheer in a number of characters. In S. caesia the leaf is oblong elliptic or lanceolate, the male flower has entire or 2-3 lobed gland, the filament is partly or completely connate. The female flower has only one gland, the stigma is entire or 2-lobed. S. sclerophylla has elliptic, ovate or obovate to suborbicular leaves, the male flower has 2 glands, which are sometimes divided, the filaments are free; the female flower also has 2 glands, sometimes divided, rarely only one gland and the stigma is 4-lobed (F. Zhenfu, Z.Shidong & A.K.Skvortsov, l.c.).
Further study of the two taxa seems necessary in order to evaluate the criteria objectively.