Triosteum, commonly known in American English as horse-gentian[2] or, less commonly, feverwort, and, in Standard Chinese as 莛子藨属 (ting zi biao shu), is a genus of flowering plants belonging to the family Caprifoliaceae.

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.

[8] American species : the dried and roasted fruits have been occasionally used as a substitute for coffee; but they are chiefly valued for their medicinal properties, the roots having been used as an emetic and mild cathartic.

[10][11] Five monoterpene indole alkaloids (vincosamide-6′-O-β-d-glucopyranoside (1), vincosamide (2), strictosamide (3), strictosidine (4), and 5(S)-5-carboxystrictosidine (5)), two monoterpene diglycosides ( see Glycoside ) (urceolide (6) and 4(S)-4-hydroxyurceolide (7))[12] and 10 iridoids, ( triohimas A–C, naucledal, secologanin dimethyl acetal, grandifloroside, sweroside, loganin, vogeloside and (E)-aldosecologanin ) have recently been isolated from the roots of Triosteum pinnatifidum Maxim.

Most of the iridoids in question were derived from loganin or secologanin with a glucose moiety at C-1 position and these findings indicate a close relationship between the genera Triosteum and Lonicera, and support the viewpoint that the iridoids derived from loganin or secologanin could be considered chemotaxonomic markers for the family Caprifoliaceae.