Salicaceae

Wall. ex Andersson

Garh 07 395 2 ergebnis
India Garhwal Khiar Kutti 3950m, June

Description

Salix lindleyana is a high-altitude dwarf willow distributed across the Himalayas from Pakistan through northern India, Nepal, and Bhutan to southwest China (Xizang, Yunnan) and northern Myanmar. GBIF records approximately 773 occurrences, concentrated in the alpine zones of the western and central Himalayas. The species is a characteristic element of subnival and alpine habitats at 3,500–5,200 m elevation, growing on moraines, scree slopes, stream margins, and moist alpine meadows. At Khiar Kutti in Garhwal at 3,950 m, it forms prostrate mats on gravelly substrates near glacial meltwater channels, flowering in June as the snowpack recedes and summer warmth permits a brief growing season.
Salix lindleyana is a prostrate, creeping deciduous shrub rarely exceeding 5–15 cm in height. Stems are slender, woody, rooting at the nodes, spreading laterally to form dense mats up to 1 m or more across. Leaves are small, elliptic to obovate, 5–15 mm long, entire or obscurely crenulate, glabrous at maturity, bright green above and slightly glaucous beneath. Catkins are terminal, erect, 1–3 cm long, appearing with or just after the leaves; male catkins bear stamens with purple-tipped filaments and yellow anthers, while female catkins develop into capsules 3–5 mm long containing minute, comose seeds that are dispersed by wind. The entire growth form is adapted to minimise exposure to desiccating alpine winds and to capture warmth from the ground surface.
Salix lindleyana is one of the highest-growing woody plants in the Himalayas and an important pioneer species in alpine and subnival ecosystems. Its prostrate, mat-forming habit stabilises loose substrates on moraines and scree slopes, facilitating soil development and subsequent colonisation by other alpine plants. The species is named after the English botanist John Lindley and was formally described by Andersson based on Wallich's Himalayan collections. It belongs to the section Chamaetia, a group of arctic-alpine dwarf willows, and is closely related to S. serpyllifolia of the European Alps — a biogeographical parallel reflecting Tertiary migration routes between the Alpine and Himalayan orogens.

Author: Wall. ex Andersson · Sources: POWO (Kew), GBIF, Flora of China Vol. 4, Flora of Pakistan Vol. 203, Polunin & Stainton: Flowers of the Himalaya (1984)

Hand.-Mazz. ex Enander

Bhutan2014 451
Bhutan Phobjika 2810m, May

Description

Salix salwinensis is a Sino-Himalayan willow distributed from SW China (the Salween, Mekong and upper Yangtze drainages, whence the epithet) through NE India, Nepal and Bhutan, GBIF recording some 92 occurrences across the eastern Himalaya and southwestern China. It is a shrub or small tree of high-montane and subalpine habitats, growing along streamsides, in damp thickets, at forest margins and on open slopes. The photographed plant from Phobjika in Bhutan at 2,810 m (May) reflects its occurrence in the cool temperate to subalpine belt, where willows form a conspicuous component of riparian and meadow-edge vegetation.

It is a deciduous, dioecious shrub or small tree with reddish-brown to purplish, glabrous young twigs. The leaves are oblong to oblanceolate or elliptic, acute, often glaucous beneath, with finely serrate or entire margins and a short petiole, the young foliage sometimes silky. As in all willows the flowers are reduced and borne in erect catkins appearing with or before the leaves; each flower is subtended by a hairy bract and lacks a perianth, the male with two stamens and the female with a single pistil bearing a basal nectary. The fruit is a small, two-valved capsule releasing numerous comose, wind-dispersed seeds.

Salix is a large and taxonomically intricate genus in which hybridisation and clinal variation blur species boundaries; the Himalayan willows in particular require careful study of catkin and leaf characters for identification. The dioecious, catkin-bearing, anemophilous and partly entomophilous flowers, the comose seeds and the capacity for vegetative regeneration are classic adaptations of the genus to dynamic, disturbed riparian habitats. The species is not considered threatened across its montane range.

Author: Hand.-Mazz. ex Enander · Sources: POWO (Kew), Flora of Bhutan Vol. 1, GBIF, Flora of China Vol. 4, Skvortsov: Willows of Russia and Adjacent Countries