Shangwua denticulata 

Description

Shangwua denticulata is an alpine perennial herb of the Himalaya and the Tibetan plateau region, recorded from China, Nepal, India and Bhutan, with about 170 occurrences in GBIF. It is a plant of high open habitats, growing on alpine and subalpine slopes, in meadows, on screes and among rocks, generally above the treeline. The photographed plants come from the Garhwal Himalaya of India, at the Valley of Flowers (3400 m) and at Shertoli (3100 m), both recorded in September as the late-summer alpine flora comes into flower and fruit, an elevation and setting characteristic of this cold-mountain specialist.

The plant arises from a perennial rootstock and produces erect or ascending stems bearing alternate leaves; the leaves are oblong to lanceolate with toothed (denticulate) margins, as the epithet records, and are often somewhat hairy. The flower heads (capitula) are borne singly or in small clusters and are surrounded by a many-rowed involucre of bracts, the latter frequently tinged dark or purplish as in many alpine composites. As a member of the tribe Cardueae the capitula are discoid, composed wholly of tubular, purplish florets, and the achenes are crowned by a pappus of fine bristles that aids wind dispersal.

Shangwua is a small genus recently segregated from Saussurea on molecular and morphological grounds, the species formerly treated under that genus; the recombination by Raab-Straube and Wang reflects modern phylogenetic revision of the Saussurea complex. As a high-alpine thistle relative, S. denticulata is adapted to short growing seasons, intense radiation and cold, and its specialised montane distribution makes it of biogeographic interest within the rich Sino-Himalayan Cardueae flora.

Author: (DC.) Raab-Straube & Yu J.Wang · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Saussurea and allies revision (Raab-Straube)