Triosteum, commonly known in American English as horse-gentian or, less commonly, feverwort, and, in Standard Chinese as (), is a genus of flowering plants belonging to the family Caprifoliaceae. A genus of six species in total, it has three species native to North America, and three more in eastern Asia. Derivation of Genus Name The name Triosteum is a compound of the Greek tria 'three' and osteon 'bone', in reference to the three hard pyrenes ( pips / pits ) in each drupe ( berry ) - giving the meaning 'having three pits ( as hard as ) bone'. Description Triosteum spp. are perennial, herbaceous plants of rich woods. Each plant typically consists of at least one erect, round, hairy, fistular stem, 1 to 4 feet (0.3 to 1.2m) high, with opposite ovate-lanceolate entire leaves, and whitish to purplish flowers presented either in axillary whorls or terminal racemes. The fruit is a drupe. It may be white, yellow, orange, or red, depending on the species. Species Five species and one variety are currently accepted by The Plant List, and a sixth species by the Online Flora of China: Triosteum angustifolium L. - yellowfruit horse-gentian, Native to the eastern United States Triosteum aurantiacum E.P. Bicknell - orangefruit horse-gentian, native to the eastern United States Triosteum aurantiacum var. illinoense ( Wiegand ) E.J. Palmer & Steyerm. ( named for the U.S. state of Illinois ). Triosteum himalayanum Wallich. - 穿心莛子藨 chuan xin ting zi biao, native to China, Bhutan, Nepal, and India N.B. Species name listed as 'Invalid' by The Plant List (-see note below ). Triosteum perfoliatum L. - feverwort, Native to the eastern United States Triosteum pinnatifidum Maxim., 莛子藨 ting zi biao, native to China and Japan Triosteum sinuatum Maxim., 腋花莛子藨 ye hua ting zi biao, native to east Asia N.B. A problem exists in relation to the name Triosteum himalayanum Wallich., which has been applied to a specimen of the ( unrelated ) Lasianthus hirsutus belonging to the genus Lasianthus of the family Rubiaceae : see link below to species pages in Online Flora of China 'Triosteum himalayanum ' and 'Lasianthus hirsutus'. Ornamental Value Certain species in the genus are sometimes cultivated for their colorful fruits, although the plants have been characterised as 'somewhat weedy perennials' and their flowers are, in general smaller and less showy than those of the related genus Lonicera, the Honeysuckles. Uses American species :