Wigandia caracasana

Wigandia caracasana, the Caracus wigandia, is a species of ornamental plant. It is an evergreen that grows to a height of up to 3 metres (10 ft). It has purple flowers in large clusters from spring to autumn. Some sources treat it as a variety of the species Wigandia urens. Native to Central America, it is thought to be naturalized in southern California as a garden escape. It is commonly grown in gardens, and thrives best in a mixture of loam and peat. Cuttings in sand will strike if placed under glass and in heat.

The caracus wigandia can cause severe contact dermatitis. A substance that it secretes, 2,3-dimethoxy-geranyl- 1,4-benzoquinone (consisting of a quinonoid ring with a 10 or 11 carbon-membered side chain) is a remarkably strong sensitizer, which is found nowhere else in the plant kingdom. It has been described as approximating an "ideal allergen".