Floral Ecology and Reproductive Biology of Pterospermum Reticulatum Wight and Arn. (sterculiaceae): A Vulnerable Tree Species of Western Ghats of India

Abstract

Pterospermum reticulatum Wight and Arn is a vulnerable according to IUCN red list category (1998). In the present study observations were made on floral ecology and reproductive biology of Pterospermum reticulatum at Pilikula reserve forest, Mangalore, Karnataka during 2012-2013. The peak flowering was observed during February to April and anthesis occurred in the even ing between 18:30 -22:30hrs. Inflorescences in terminal or axillary fascicles, Flowers are white colour and 5 petals and 5 linear sepals. Stamens are 15, in group of five. Fruits are capsule, brown, 5-angled and 5-valved, development of fruit to dehiscence was observed. Pollen production per flower was counted 3, 93499.9 and pollen ovule ratio was 1: 393500. Floral biology including the stigma receptivity, pollen viability, pollen germination and pollen tube growth were recorded during the flowering period. Macro and Micro nutrients of the soil collected from the rhizosphere were analyzed. The factors responsible for declining of the population of Pterospermum reticulatum are discussed