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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. [ABSTRACT FROM AUTHOR]

Rock outcrops support specialist plant communities that are often adapted to highly seasonal climates and heterogeneous soil cover. However, the relationship between environmental parameters and plant functional types remains unexplored in many regions of the world, including the Northern Western Ghats (NWG) in India. In the present work, we characterised the vegetation of high and low elevation rock outcrops in the NWG, and investigate the relationship between plant functional types and environmental variables. Vegetation surveys were conducted on 16 high elevation and 14 low elevation sites using a transect and quadrat method. Floristic data were used to calculate plant diversity and plant functional type abundance. The relationship between vegetation and climatic (temperature, precipitation) and soil (soil carbon and nitrogen) variables was explored using cluster and ordination analysis. Rock outcrop sites were grouped into two clusters based on elevation, distance from the sea and mean diurnal range. Plant functional type abundance was related to macro-environmental variables such as temperature, precipitation and soil nutrients such as carbon and nitrogen. We inferred that the distribution and dominance of different plant functional types in the NWG are related to primarily by elevation (a proxy for temperature) and distance from the sea. [ABSTRACT FROM AUTHOR]

• Tropical inselbergs are centers of diversity for desiccation-tolerant mat-forming monocots. • Cyperaceae, Poaceae and Velloziaceae are the main Poikilohydric monocot families on tropical inselbergs. • Species diversity and endemism of Poikilohydric monocot-mats varies considerably along the tropics. Desiccation-tolerant mat-forming monocotyledons (DTMFM) are typical constituents of the vegetation of tropical inselbergs. The latter are old granitic / gneissic rock outcrops that rise abruptly above the surrounding landscape. Due to unpredictable droughts, they are centers of diversity for dry adapted species such as vascular resurrection plants (poikilohydric species). Carpet-like mats formed by highly specialized DTMFM occur on open, partly steep slopes where they are firmly glued to the underlying rock. These mats are widespread on both Neotropical (mainly Brazil) and Paleotropical (Africa, Madagascar, India) inselbergs. Within angiosperms, exclusively members of Cyperaceae, Poaceae and Velloziaceae are DTMFM. Here, we compiled 32 DTMFM species on tropical inselbergs. Nevertheless, since ecophysiological studies focused on this particular group of plants are still incipient, we expect that many more species display this strategy on tropical inselbergs. Our overview provides updated insights into selected biogeographical, ecological and molecular aspects of DTMFM. [ABSTRACT FROM AUTHOR]