Buch.-Ham. ex D.Do
Description
Swertia angustifolia is a slender annual or biennial herb widespread across the Himalaya and montane Asia, recorded from China, India, Nepal, Myanmar, Thailand, Pakistan, Bhutan and beyond, with peripheral records (KR, ZA, SG, US) reflecting introduction or cultivated material. Its roughly 1,000 georeferenced collections make it one of the better-documented species in this group, ranging through the subtropical to temperate hill belt. It grows on open grassy slopes, fallow fields, roadsides, forest margins and disturbed ground, often as a pioneer of seasonally moist sites. The photographed plant from Bhutan near Wangdi at 2700 m, flowering in September, is characteristic of its autumn flowering at the close of the monsoon.
It is an erect, glabrous herb with a slender, quadrangular, usually much-branched stem arising from a thin taproot. The opposite leaves are narrowly lanceolate to linear, sessile, entire and acute, the epithet angustifolia referring to their narrowness. The flowers are numerous, small and borne in a lax, leafy, paniculate cyme. The corolla is rotate and typically four- or five-merous, white to pale greenish or purplish, each lobe bearing one or two nectary glands (foveae) fringed with hairs near its base, a diagnostic feature of the genus. Stamens equal the corolla lobes in number, and the superior, one-celled ovary develops into a many-seeded capsule.
Swertia is a large genus of the gentian family, richest in the Sino-Himalayan region, and many species (notably the chiretta group) are economically important in traditional medicine for their intensely bitter secoiridoid glycosides. S. angustifolia is a common, weedy, wide-ranging species of no conservation concern, frequently colonising agricultural and disturbed land. Its small, fly- and bee-pollinated flowers and prolific seed set underpin its success as a montane ruderal.
Author: Buch.-Ham. ex D.Do · Sources: POWO (Kew), GBIF, Flora of China Vol. 16, Flora of Bhutan Vol. 2, Flora of Nepal, Clarke's Monograph of Asiatic Gentianaceae