PHENOLOGY AND FLORAL BIOLOGY OF HUMBOLDTIA DECURRENS (FABACEAE) - AN ENDEMIC LEGUME OF SOUTHERN WESTERN GHATS

摘要

A study on phenology and floral biology of Humboldtia decurrens, an endemic plant of Southern Western Ghats was carried out in wild conditions. The plant starts flowering in the month of November and extends up to May and reaches a peak during March.The flowers are pink or white coloured and open in the early morning between 0530-0630h. Stigma remains receptive at the time of anthesis and extends up to 8 hrs after anthesis. Different pollen viability tests indicated that 75-80% pollen grains are viable on the day of anthesis and its viability gradually decreased on successive days after anthesis. Honey bees, stingless bees, butterflies and ants are the major floral visitors of Humboldtia decurrens. Habitat degradation, scarcity of pollinators, lowinsect visitation rate, poor fruit set could be the reasons for its narrow distribution in the natural habitat.