Desiccation‐tolerant vascular plants from Western Ghats, India: review, updated checklist, future prospects and new insights

Abstract

Desiccation‐tolerant vascular (DT) plants are predominant occupants of rock outcrops in tropical regions. Though rock outcrops are common landscapes in the Western Ghats (WG), a biodiversity hotspot in India, knowledge of DT plants in the region is poor. This study provides an overview of Indian DT vascular plants, emphasizing the WG, and includes an inventory of species with their habitat preferences. Outcrop species were scrutinized for their DT properties by seasonal field observations, followed by relative water content estimation protocols. The inventory revealed 62 DT species, many more than the earlier known nine species. Nine genera of DT plants are reported as new also in a global perspective, and Tripogon capillatus represent the first record of an epiphytic DT angiosperm. We also provide the first field observation‐based proof of DT properties of the gesneriad Corallodiscus lanuginosus. Of the 62 species, 16 are Indian endemic, and 12 are exclusive to Western Ghat outcrops, highlighting WG's importance as a global DT hotspot. In addition to rock outcrops, partially shaded sites in forests are crucial habitats for DT species. This pioneering inventory addresses India's need for more knowledge on DT plants and opens new research avenues.