Roxb.
Description
Cuscuta reflexa, the giant or Asian dodder, is a widely distributed parasitic vine ranging across South, Central and Southeast Asia and beyond, with GBIF documenting more than 1000 occurrences from India, Pakistan, Nepal, China, Afghanistan, Sri Lanka, Bangladesh, Bhutan, Thailand and Myanmar among others. It occurs from the plains into the lower hills, the photographed plant deriving from Trashigang in eastern Bhutan at 1150 m in October. As an obligate stem holoparasite it has no true habitat preference of its own but follows that of its hosts, smothering shrubs, hedges and trees along forest margins, scrub, roadsides and cultivated ground in warm subtropical settings.
The plant is a leafless, rootless twining parasite with stout, fleshy, glabrous stems coloured yellow, orange or reddish, attaching to hosts by means of haustoria that penetrate the vascular tissue. Leaves are reduced to minute scales and chlorophyll is largely absent. The flowers are comparatively large for the genus, white to creamy, fragrant, and crowded in dense lateral racemes; the campanulate corolla has reflexed lobes (hence the epithet) and bears characteristic infrastaminal scales within the tube. The fruit is a globose capsule capped by the persistent corolla and opening circumscissily to release several seeds.
Cuscuta (now placed within an enlarged Convolvulaceae rather than a segregate Cuscutaceae) comprises around 200 holoparasitic species. C. reflexa is economically significant as a pest of cultivated and ornamental plants, yet is simultaneously valued in traditional South Asian medicine. Far from threatened, it is locally abundant and weedy; its parasitism exerts measurable effects on host vigour and on plant-community structure where it proliferates.
Author: Roxb. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of Pakistan, Flora of British India (Hooker), Yuncker Monograph of the Genus Cuscuta