Ten alkaloids (I-X), five β-phenethylamines, two tetrahydroisoquinolines, and three indole-3-alkylamines, have been isolated from Desmodium tiliaefolium. Chemical transformations, spectral (UV,IR, NMR, MS) evidence, and in most cases comparison with reference materials established their identity as tyramine (I), hordenine (II), 3,4-dimethoxy-β-phenethylamine (III), N,N- dimethyl-3,4-dimethoxyphenethylamine (IV), N-methyl-3,4-dimethoxy-β-hydroxyphenethylamine (V), salsoline (V1), salsolidine (VII), tryptamine (VIII), abrine (IX), and hypahorine (X). Alkaloid (V) is a new naturally occurring compound, while no tetrahydroisoquinoline alkaloid has been encountered before in this genus. This is the first time that three different types of alkaloids have been reported in a single legume species. In addition to the above alkaloids, four quaternary β-phenethylamines and tetrahydroisoquinoline alkaloids have been detected, and choline and betaine have been isolated from the water-soluble alkaloid fraction of the roots. © 1973.