Floral resources of Karnataka: a geographic perspective

Abstract

We compiled the data on the floral resources of Karnataka from diverse published sources and analysed the geographic patterns of distribution of floral diversity. Our database shows that Karnataka harbours 4758 species from 1408 genera and 178 families and accounts for about 27 per cent of the country's floral diversity. We computed the 'endemicity value' of different districts based on the number of endemic species (those restricted to a maximum of five districts) harboured by them and found that the most species-rich districts (viz. Uttara Kannada, Dakshina Kannada, Mysore, Hassan, Udupi and Kodagu) were also characterized by high values of endemicity while the species-poor districts had low values of endemicity. However, the relation between the species richness and endemicity of the districts was not linear; the species richness increases abruptly at lower levels of endemicity but plateaus off later at high levels of endemicity. Based on the number of species packed into the families, all the 27 districts segregated distinctly into three clusters that geographically correspond with the three major agro-climatic zones of the state. Our analysis showed that though the districts along the Western Ghats are florally rich, those along the dry tracts also harbour certain unique elements of the flora; thus these dry zone districts appear to be as important as those along the Western Ghats in conserving the floral resources.