C.B.Clarke ex Hook.f.
Description
Impatiens florigera is a balsam of the eastern Himalaya, recorded by GBIF (about 29 occurrences) from India, Bhutan and Nepal. It is a herb of moist, shaded habitats in the subtropical and warm-temperate broadleaved forest belt, growing on damp banks, by streams, in forest clearings and along shaded roadsides where soil moisture is high through the monsoon. The illustrated plant was photographed in Bhutan at Zemgang at about 1800 m in October, an autumn-flowering montane forest locality characteristic of the species, which blooms towards the close of the monsoon when many Himalayan Impatiens reach their flowering peak.
The plant is a succulent, glabrous annual with a translucent, watery stem that is often reddish at the swollen nodes and branches freely. The leaves are alternate, ovate to elliptic, with a crenate-serrate margin and shortly acuminate apex, narrowed to a petiole that may bear a few stipitate glands. The flowers are zygomorphic and showy, borne on slender axillary peduncles; each has the balsam structure of three sepals, the lowest enlarged into a spurred boat-shaped lip, and five petals forming a standard and two lateral united pairs, typically pink to purplish. The fruit is a fleshy, club-shaped capsule that dehisces explosively, its valves coiling abruptly to scatter the seeds.
Impatiens is one of the largest genera of flowering plants and especially diverse in the Himalaya, where numerous narrowly distributed species occupy moist forest habitats and are distinguished by fine differences in flower form, spur shape and indumentum. I. florigera belongs to this rich eastern Himalayan radiation. As a monsoon-dependent annual of moist forest it is locally frequent within its range; its explosive seed dispersal and insect pollination are typical of the genus.
Author: C.B.Clarke ex Hook.f. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Annotated Checklist of the Flowering Plants of Nepal, Grey-Wilson's monograph Impatiens of Africa and revisional studies of Asian Impatiens