Reproductive Biology of Elaeocarpus blascoi Weibel, an Endemic and Endangered Tree Species of Palni Hills, Western Ghats, India

Elaeocarpus blascoi Weibel is a lesser known endemic tree species growing in the Vattakanal shola forest of Palni Hills, Western Ghats, India. A study on reproductive biology of the species was conducted in the natural habitat to study its phenology, floral biology, pollen biology, fruit set and seed germination. Flowers are bisexual, anther dehisces 2-3 hours after anthesis and stigma becomes receptive on the day of anthesis and extends up to 6 days. Breeding experiments confirmed that the species permits autogamy and geitonogamy. Six different pollinators were observed during peak flowering period and Apis dorsata (honey bee) was found to be an effective pollinator and it takes 55 ± 15 sec per flower. Percentage of fruit set observed in the natural habitat was 78% and seed germination rate was found to be less than 5% in the natural habitat. Tests showed that more than 70% of seeds lost their viability after a year and most of the seeds were infested with Fusarium sp., Lasiodiplodia sp. and Penicillium sp. Further, the natural habitat of the species is altered by commercial plantations, tourism and urbanization in the Palni Hills, which leads to their reduction.