The genus Solena Lour. is redefined, and its 3 species and 1 subspecies are keyed out and described: S. amplexicaulis occurs in S India, S. heterophylla, with 2 subspecies is widespread, but does not occur in S India, and S. umbellata (Klein ex Willd.) W.J. de Wilde & Duyfjes, comb. nov., occurs in S India and Sri Lanka. The status of S. heterophylla subsp. napaulensis (Ser.) W.J. de Wilde & Duyfjes, comb. & stat. nov. needs further study as this subspecies is very similar to the more widespread subsp. heterophylla, but it is distinct by sigmoid thecae. Solena amplexicaulis is taxonomically more distinct from the other two species of Solena. In southern India Kedrostis foetidissima much resembles Solena in general habit, especially by the more or less amplexicaul leaves, and therefore it is discussed and keyed out against Solena.