LOASACEAE

mostly tropical American plant family of about 15 genera and more than 250 species, many with painfully stinging hairs but beautiful and often bizarre flowers in red, orange, yellow, or white. Loasaceae species are frequently twining and mostly herbaceous. The genus Loasa, with about 100 species from Mexico to the Andes, has nettle-like stinging hairs that can result in discomfort for days; its oddly formed flowers have five pouchlike yellow petals covering united stamens that form coloured nectaries. The closely related Caiophora (or Cajophora), with about 65 tropical American species, like the Loasa, mostly grows in rocky slopes of cool Andean areas. The clusters of red-orange, pouchlike petals of C. lateritia measure about 5 centimetres (2 inches) across, on a twining plant up to 6 metres (about 20 feet) long. Species of the genus Mentzelia have nonstinging but hooked hairs. Some have satiny orange blooms smaller than the 6-cm, cupped, five-petalled flowers of blazing star (M. lindleyi) of western North America. The yellow, fragrant blooms of blazing star open in the early evening. The two species of Kissenia, the only non-American genus, are native to West Africa, East Africa, and western Asia.