<i>Ophiorrhiza echinata</i> , a new species of Rubiaceae from the southern Western Ghats, India

A new species of the genus Ophiorrhiza (Rubiaceae) is described and illustrated from the Idukki District of Kerala, Western Ghats, India. The new species is allied to Ophiorrhiza caudata C.E.C.Fisch. and Ophiorrhiza munnarensis C.E.C.Fisch, but differs in having echinate young stem, leaf lateral nerve pairs 8–14, triangular, caducous stipules, 14.0–23.0 mm long homostylous flowers, dissimilar bract and bracteole without midrib, ovate calyx lobes, stamens adnate to the base of corolla tube, 4.5–5.0 mm long filaments, oblong stigma, and oblate seed. A detailed description, colour photographs, comparison, phenology, distribution, conservation status, and key to allied taxa are provided.