Hook.f. & Thomson
Description
Eutrema himalaicum Hook.f. & Thomson is an alpine crucifer of the high Himalaya and adjacent China, recorded from China, India and Bhutan, with around 249 georeferenced occurrences in GBIF (further scattered records reflect cultivation and herbarium holdings). It occupies moist alpine meadows, streamsides, seepage slopes, gravelly flats and rocky places near snowmelt, generally between about 3500 and 4800 m. The photographed plant was found at Yumthang in Sikkim at about 3800 m in June, in the lush, well-watered subalpine to alpine turf that this small herb favours as the snow recedes.
The plant is a slender annual or short-lived perennial with erect or ascending, often glabrous stems arising from a basal rosette. The leaves are simple, the basal ones petiolate with ovate to deltoid or somewhat hastate blades (recalling the form once distinguished as E. deltoideum), the cauline leaves smaller and shortly stalked to subsessile. The flowers are small and borne in terminal racemes; each has four white petals arranged in the cruciform pattern typical of the family, four free sepals and the tetradynamous stamens of the Brassicaceae. The fruit is a slender silique, the seeds in a single row within each locule.
The genus Eutrema, which includes the cultivated wasabi (E. japonicum), has been substantially recircumscribed by molecular studies, absorbing several formerly segregate Himalayan genera; this accounts for the species' nomenclatural history and the alternate epithet seen on the source page. As a snowbed and seepage specialist it is adapted to short, cool growing seasons. The species is fairly widespread within its alpine band and not of conservation concern, though sensitive to habitat disturbance.
Author: Hook.f. & Thomson · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Al-Shehbaz revision of Eutrema and Tribe Eutremeae, Hara Flora of the Eastern Himalaya