A n estimated 238 species of annuals and perennials to be found in the temperate and subtropical regions of the world. They are tufted to clump to mat-forming with mainly trifoliate, stipuled leaves and usually dense, globular, ovoid or cylindrical heads of tiny, slender pea flowers.
Surprisingly few members of this large genus are cultivated on the rock garden and most of those that can be, do not look in keeping, T. uniflorum being an exception. Well drained, moderately fertile soil and a sunny site is required. Propagation by seed or division in spring, and non-flowering basal shoots can be tried as cuttings in late spring or summer. (all perennials)