Two new species of the Asiatic genus Polypleurum (Podostemaceae – Podostemoideae), Polypleurum prostratum and Polypleurum disciforme from Kerala, India are described. They differ in the shape of the thalloid plant body from the other species of Polypleurum. A key to the species occurring in India is provided. Though sharing the habitat with some other species of the Podostemaceae, the new species inhabit special niches in the rocky riverbed. – The chemical components of the (hard) water in which they grow differ considerably from what is known from black water rivers of the New World. The results thus widen considerably our knowledge of the ecological needs of Podostemaceae.