Phylohydrax includes two species of rather succulent, small, prostrate, herbaceous plants that live on shores of the Indian Ocean. These species were previously included in Hydrophylax, but Puff (1986) separated them with one species from southern Asia remaining in Hydrophylax. Another genus of small-leaved succulent Rubiaceae that grows near the seashore in our region is Gomphocalyx. Dessein et al. (2005) documented the morphology, anatomy, biology, and distribution of both of these genera. They also demonstrated that Phylohydrax and Gomphocalyx are closely related to each other and also to genera that have been included in Hedyotideae, rather than the genera of Spermacoceae s. str. where these genera have usually been classified.