Two new subgenera and one new species in the genus Drosanthemum

Based on extensive morphological studies in more than 1,000 populations, two new subgenera are established in the genus Drosanthemum: D. subg. Decidua H.E.K.Hartmann and subg. Quadrata H.E.K.Hartmann; in the latter, a new species is described: D. tetramerum H.E.K. Hartmann. A key and descriptions of the included species are provided.