Endemism and sexual systems in the evergreen tree flora of the Western Ghats, India

This study reports the endemism and sexual system in the wet evergreen tree flora of the Western Ghats. A total of 656 species from 66 families and 231 genera were listed. This included a gymnosperm family (Podocarpaceae) and a monocot family (Arecaceae). No family was endemic to the Western Ghats, but 352 species (53%) from 43 families and five genera were endemic. Nearly 35% of the families had no endemics. The largest families with endemics were Dipterocarpaceae (92%), Anacardiaceae (84%), Lauraceae (72%), Fabaceae, Rubiaceae and Myrtaceae (68%). The top five contributing families in the tree flora of the Western Ghats were Euphorbiaceae, Lauraceae, Rubiaceae, Myrtaceae and Annonaceae. The 656 species were largely hermaphrodites (57%) followed by dioecious (20%), polygamous (16%) and monoecious species (5%). The rate of dioecy reported in this study (20%) is higher than reports for Puerto Rico (18%) but lower than the Malaysian rainforest (26%). Structurally, like the Neotropical forests, most evergreen forest types of the Western Ghats could be classified into four ensembles. Yet, the Western Ghats had fewer species than other tropical and Neotropical forests. The proportion of endemics in the ensembles of the Western Ghats ranged from 34% (ensemble IV) to 14% (ensemble I).