Benth.
Description
Elsholtzia pilosa is a wide-ranging Asian mint distributed from the Indian Himalaya, Nepal and Bhutan eastward through Bangladesh, Myanmar, Thailand and Vietnam to southern China, with nearly 400 GBIF occurrences indicating it is a frequent component of its region. It is a plant of open, disturbed and seasonally moist ground, growing along forest margins, on grassy banks, in fallow fields, by paths and on damp slopes, often as a weedy colonist of cultivated and waste land. The plant figured from Bora in Garhwal, India, at about 2200 m in September is typical of its montane range of roughly 1500-3000 m, the autumn flowering coinciding with the close of the monsoon.
It is an erect, aromatic annual herb with a quadrangular, usually pilose stem branching from the base. The leaves are opposite, ovate to lanceolate, with a serrate-crenate margin, an acuminate apex and a cuneate base tapering to a slender petiole, sparsely hairy and gland-dotted. The small flowers are crowded into dense, one-sided, spike-like terminal verticillasters, each subtended by a bract; the corolla is purplish to pinkish-white and bilabiate, with the four stamens exserted as in the genus. The calyx is tubular and ribbed, becoming enlarged in fruit and enclosing the four smooth, ovoid nutlets characteristic of the mint family.
The epithet pilosa refers to the soft, spreading hairiness of the herbage. Elsholtzia is a mainly eastern Asian genus of aromatic herbs and subshrubs, several species of which are used medicinally and as flavourings, the essential oils giving the foliage its pungent scent. As a pioneer of disturbed ground, E. pilosa is well adapted to anthropogenic habitats, which accounts for its broad and locally abundant distribution across the Himalaya and southern China.
Author: Benth. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Hooker Flora of British India, Press Labiatae of the Himalaya