Roxb.
Description
Erythrina arborescens is a Himalayan to Southeast Asian coral tree distributed across China, India, Nepal, Bhutan, Myanmar, Bangladesh, Japan and Thailand, with about 369 GBIF occurrences spanning this wide subtropical to warm-temperate range. It grows in open broad-leaved forest, forest margins, valley slopes and disturbed ground, generally from about 1300 to 3000 m. The trees photographed near Wangdi Phodrang in Bhutan at about 1900 m in October and at about 2500 m in September illustrate its mid-elevation valley habitat, where its scarlet flower spikes appear after the leaves toward the close of the monsoon.
The species is a small to medium-sized deciduous tree with a stout trunk and branches armed with scattered conical prickles. The leaves are alternate and trifoliolate, with broadly ovate to rhombic leaflets, the terminal one largest, on a long prickly petiole. The inflorescence is a dense terminal raceme of large, showy, bright red papilionaceous flowers in which the broad standard petal is conspicuously enlarged while the wings and keel are reduced, an arrangement adapted to bird pollination. The fruit is an elongate, torulose, dehiscent legume constricted between the few shining red-brown seeds.
Erythrina is a pantropical genus of about 130 species notable for ornithophilous, nectar-rich flowers and seeds containing toxic isoquinoline alkaloids. E. arborescens is among the few species extending into temperate Himalayan elevations, its post-monsoon flowering and copious nectar attracting sunbirds and other nectarivorous birds that serve as pollinators. Widely distributed and tolerant of disturbance, it is of least concern; it is locally valued as a shade and ornamental tree and features in traditional medicine across its range.
Author: Roxb. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Krukoff & Barneby studies of Erythrina