Floristic studies on monocotyledons of Idukki district, Kerala

Abstract

Survey and documentation of the floristic wealth of a region is a prerequisite for planning the proper utilization of its potential plant resources on one hand and to conserving the depleting genetic resources on the other. Idukki, the ‘Cradle of plantation crops’ and ‘Home to nature’ is the largest district of Kerala covering an area of 4,612 km 2 and is one of the richest parts of southern Western Ghats with 5 national Parks and 3 wildlife sanctuaries. The vegetation comprises evergreen forests, semi-evergreen forests, moist deciduous forests, dry deciduous forests, shola forests, grasslands, and forest plantations. Anamudi ‘the Everest of South India’ is located in this district. Monocots are much diverse and one of the major groups of flowering plants in the Idukki district. This thesis discusses the taxonomy, diversity, endemism, and recommendations for the conservation of monocotyledons in the Idukki district.During the present study, a total of 652 species in 248 genera under 28 families were collected. Out of the total plants, 592 species occur in the wild and 58 were cultivated. It is the largest number of taxa of monocotyledons compared with the rest of the districts. 45% of the state’s monocotyledon diversity occurs in this district, which indicates the species richness of the district. Among the 592 wild taxa, 213 are included in IUCN Red List for threatened plants. The study area harbours 138 (23%) endemic species. 26 species are introduced, majority of them are introduced for ornamental and fodder purposes, but most of them become aggressive colonizers and threaten the habitat of the native species. During the investigation, three new species: Eriocaulon vamanae Dani & Nampy and Burmannia munnarensis Dani & Nampy were described, while Ariopsis idukkiana sp. nov. is communicated. Burmannia indica was rediscovered after 110 years. Seven species are new records to Kerala and two are new reports to the study area. P. neilgheriensis and P. courtallensis were reinstated.Since Idukki is one of the major tourist destinations, the majority of the hill stations are accessible to tourists. The development of tourism actively and passively affects the floral and faunal diversity through construction activities, road widening, pollution, etc. Moreover, the extreme climate fluctuations and their resulting flood, fire regimes, snowfall, landslides, etc. lead to habitat fragmentation and destruction. The study provided a comprehensive account of the monocotyledon diversity of Idukki, which provides insights into the importance of conservation, identification, impact assessment, research, management decisions, and policy formulation.