Salix austrotibetica N. Chao (1980: 23)

He, Li, Liao, Shuai & Zhang, Zhixiang, 2015, Nomenclature and taxonomy of Salix floccosa, S. opsimantha and S. austrotibetica, Phytotaxa 201 (2), pp. 158-164 : 160-162

Salix austrotibetica N. Chao (1980: 23) ( Figs. 1D and 2A–J )

Type:— CHINA. Xizang, Mêdog County, Duoxiongla, 3300 m, 28 August 1977, T.P. Yi 77221 (holotype SCFI!, ♀).

Heterotypic synonym:— Salix floccosa Wang & Fang (1984: 197) , non Burkill (1899: 529), S. floccosa Fang et al. (1999: 210) , non Burkill (1899: 529).— S. floccosa var. leiogyna P.Y. Mao & W.Z. Li (1987: 49) . Type: CHINA. Yunnan, Weixi County, Nanguogong, 3910 m, 10 July 1937, T. T. Yu 8833 (holotype KUN- 1208253!, isotypes KUN!, PE×2!, ♀).

Shrubs, 0.2–0.5 (1.5) m. Branchlets at first sparsely white villous, glabrescent. Buds glabrous. Petiole 0.3–1.1 cm, at first villous; leaf blade obovate-elliptic, or oblanceolate, 2–5.4 × 1.1–2.5 cm, abaxially pale, pruinose, villous when young, glabrescent, adaxially green, villous, glabrescent, base cuneate, margin irregularly glandular dentate or entire; lateral veins ca. 5 each side of raised midvein (abaxially). Catkins at apex of branchlets; male catkin 1.3–2.8 × 0.5–1 cm; peduncle 2.3–6 cm, with 6–11 leaflets; female catkin 1.3–3.3 cm; peduncle 2.5–10.1 cm, with 5–14 leaflets, fruiting catkins persistent through the winter; floral bract broadly obovate or long obovate-elliptic, 1.5–3.2 mm, abaxially sparsely hairy, or only ciliate, apex rounded, subtruncate or retuse. Male flower: abaxial gland 0.44–1.15 mm, adaxial gland narrowly ovate or square, 0.53–0.97 mm; stamens 2; filaments distinct, 3.4–5.4 mm, glabrous to hairy on proximal 1/2. Female flower: adaxial gland ovate or narrowly ovate, rarely 2-lobed, 0.53–1.3 mm, abaxial gland rarely present; stipe 0.24–0.56 mm; ovary ellipsoid, glabrous, pruinose, partly downy, or densely downy; styles 0.8–1.9 mm, distinct; stigmas 0.1–0.36 mm, 2-lobed. Capsules 1.6–4.6 mm.

Phenology:—Flowering early June to early August, and fruiting in August and September.

Habitat:—Mountain slopes. 2400–4400 m.

Distribution:—Southern, southeastern Xizang and northwestern Yunnan.

Note:— Chao (1980) described S. austrotibetica as a mid shrub, with glabrous pruinose ovary ( Fig. 1D ). However, we have observed glabrous, pruinose, partly downy or densely downy ovary in natural populations of S. austrotibetica , which occurs in southeastern Xizang and northwestern Yunnan ( Fig. 2 A–J ). Precisely how to treat ovary hairiness in determining correct taxonomy requires more research. Based on the observed variation in ovary hairiness, a more broadly circumscribed S. austrotibetica has glabrous, pruinose, or partly downy to densely downy ovary, and a wider geographic range in Xizang and Yunnan.

Mao & Li (1987) described S. floccosa var. leiogyna based on T.T. Yu 8833 from Weixi County, Yunnan. The specimens of T.T. Yu 8833 has villous leaves, abaxially pruinose, terminal catkin, glabrous ovary, which fit S. austrotibetica . S. floccosa var. leiogyna is here synonymized under S. austrotibetica .

Figures

FIGURE 1. Type specimens of S. floccosa, S. spodiophylla, S. opsimantha and S. austrotibetica. A. lectotype of S. floccosa (Delavay 4678, P-00761020); B. type of S. spodiophylla (Forrest 5833, PE-00742970), leaf blade abaxially (b1); C. syntype of S. opsimantha (Wilson 2139, A); D. holotype of S. austrotibetica (T.P.Yi 77221, SCFI), female flowers (d1).

FIGURE 2. S. austrotibetica. A–J. variation in ovary hairiness, from three populations; A (L. He & S. Liao PH20120807-06, BJFC), B (L. He & S. Liao PH20120807-11, BJFC), C (L. He & S. Liao PH20120807-05, BJFC), and G–H from Mingyong Glacier, Dêqên County, Yunnan; D (L. He & S. Liao PH20120820-01, BJFC) and I–J from Songlinkou, Mainling County, Xizang; E (Yarlung Zangbo Expedition Team 406, BJFC) and F (Yarlung Zangbo Expedition Team 398, BJFC) from Duoxiongla, Mêdog County, Xizang.