FLOWERING PHENOLOGY AND POLLEN BIOLOGY OF OPHIORRHIZA RADICANS : AN ENDANGERED HERB OF SOUTHERN WESTERN GHATS

摘要

Ophiorrhiza radicans is a heterostylous Rubiaceous plant of Southern Western Ghats. The term heterostyly is generally used to describe the condition characterised by two or three different morphs of flowers in a given species with respect to style length in relation to position of stamens. The species is an endangered annual creeping herb which exhibit distyly with pin and thrum flowers. Here, we compare the floral phenology and pollen biology of pin and thrum morphs of Ophiorrhiza radicans. The species starts flowering in the month of July and extends up to December. Anthesis was noticed in the early morning between 0545-0830h. Pollen fertility and viability studies indicated that thrum pollen grains are more fertile and viable than pin pollen grains. The most striking features are the expression of female and male characters of pin and thrum morphs respectively.