Botarrical Joumal of the Linnean Society, 72: 269-28j. With 1 figure June 1976 : t' { I The Pteridophytes of Rod"igoo Island D. LORENCE The Mauritius Herbarium, Mauritius Sugar Industry Research Institute, Rdduit, Mauritius* Accepted for publication March 1976 A review of the pteridophytes of Rodrigues and their ecology is presented, based on a brief survey in 1973 and earlier records. Twenty-five species are listed, two of the Selaginella species being endemic. Three additional species have been recorded as native or naturalized: Lycopodium cemuum, Ophioglossum pendulum and Salvinia molesta, Four species not recorded since 1879 are presumed extinct. Nature reserves are needed to preserve the remnants of native plant communities. CONTENTS Introduction Botanical history 271 Presentdayplantcommunities . : : : : . : 271 List of species 27 5 Acknowledgements ZB3 References INTRODUCTION Rodrigues, the smallest of the three Mascarene Islands, lies on an easterly extension of the submarine Mascarene plateau some 650 km east of Mauritius, of which it is a political dependency. Situated at a laritude of 63025'E ^nd longitude 19" 42' S, it is roughly elliptic in outline with a much dissected coastline. Some 18.3 km long and 6.5 km wide, the island consists of a central mountainous basaltic ridge orientated WSW and rising to a maximum elevation of 396 m at Mt Limon. The whole of the island is hilly and cut by many radiating valleys, in the bottoms of which run streams, many of which arl seasonally dry. Rodrigues is apparently the summit of a volcano, extinct since the Pliocene-Pleistocene eras, which has undergone various changes in the land/sea level during its existence. This is suggested by the fact that the island's southern and eastern coasts are edged by fairly continuous and cave-studded strips of ' Present address, Missouri Botanical Garden, 2315 Tower Grove Avenue, St. Louis, Missouri 6311O, U.S.A. 269 243 269