Wall.
Description
Coriaria nepalensis is a shrub of the Himalaya and adjacent mountains of western China, ranging from Pakistan through the Indian Himalaya, Nepal and Bhutan to south-western China and Myanmar. GBIF aggregates around 1880 occurrences, including scattered introductions in Europe and Japan where it is grown as a curiosity. It is a vigorous colonist of open hillsides, landslips, riverbanks, terrace edges and disturbed ground, often forming thickets on poor soils between about 1000 and 3000 m. The plant from the Arun Valley of eastern Nepal at 1650 m in May is characteristic of its role as a pioneer of the subtropical to warm-temperate hill zone.
It is a much-branched deciduous shrub with arching, reddish, four-angled young branchlets. The leaves are opposite or whorled, sessile or subsessile, ovate to ovate-lanceolate, entire and conspicuously three- to five-veined from the base. The small flowers are borne in slender axillary or terminal racemes, with five sepals and five small petals; after flowering the petals enlarge, becoming fleshy and dark purple-black, closely investing the cluster of achene-like fruitlets to form a juicy, mulberry-like pseudo-fruit. These succulent infructescences are bird-dispersed but, like the whole plant, are highly poisonous, containing the convulsant sesquiterpene coriamyrtin.
Coriariaceae is a small, isolated family of the single genus Coriaria, with a remarkable disjunct distribution across the Mediterranean, eastern Asia, the Himalaya, New Zealand and the Americas, a textbook case of relictual biogeography. C. nepalensis fixes atmospheric nitrogen through root nodules harbouring the actinomycete Frankia, underpinning its success on impoverished, eroded substrates. Widespread and weedy in its native range, it is of no conservation concern, though its toxicity is locally significant to livestock.
Author: Wall. · Sources: POWO (Kew), GBIF, Flora of China Vol. 11, Flora of Bhutan Vol. 1, Flora of Pakistan, Annotated Checklist of the Flowering Plants of Nepal, Skog revision of Coriaria