Floral Biology and Pollination ecology of Rhizophora mucronata Lam in Pitchavaram, Tamil Nadu
Utchimahali Mariappan* and Nagarajan Binaibabu
Institute of Forest Genetics and Tree breeding (Indian Council of Forestry Research and Education) P.B. No. 1061, R.S. Puram P.O., Coimbatore-641002 (India) Corresponding author: utchibotany@gmail.com
ABSTRACT
Rhizophora mucronata, a blastocarpus mangrove species of Rhizophoraceae family, commonly known as red mangroves is considered as one of the keystone species in the mangrove ecosystem. However, floral biology in the taxon remains unexplored in Pitchavaram mangroves at Tamil Nadu (1°17’- 11°30’N; - 79°45’-79°50’E). Hence the study was conducted to understand the floral biology of R. mucronata. The present study hypothesised that “R. mucronata is a chasmogamous system in which anthesis time is independent of day light temperature rhythm”. The study was also aimed to understand the correlation between the abiotic factors on the pollinator visitation. Result revealed that flowers are chasmogamous and exhibit protandry. Flower opening was independent of day light temperature and occurred throughout the day. However, the duration of anthesis is very slow (8 -12 hrs). Diurnal flower visitation patterns of insects were negatively correlated to flower surface temperature (r = -0.92). It was also noticed that flowers of R. mucronata exhibit distinctive male and female phases during the floral life.