Pollination Biology of Costus woodsonii Maas (Costaceae)

Abstract

Costus woodsonii is a perennial herb, belongs to the family Costaceae under the order Zingiberales. Inflorescence terminal, flowers emerge one at a time from bright red coloured bracts of inflorescence, flowers throughout the year. Anthesis occurs between 05:00–06:00 and the average life span of individual flower is 1 day. Anther dehiscence occurs between 03:00 and 03:30 through longitudinal slit. Flowers offer both nectar and pollen to visitors. Nectar secreted both in bract and flower. Pollen grains are polyporate and remains as viable still after 13 hours after anther dehiscence. Percentage of pollen viability is high at 07:00. High percentages of pollen grains are fertile (89.7 ± 0.8%) on the day of anthesis.In vitro pollen germination is found maximum in 1% of sucrose solution. Stigma becomes more receptive at 06:00 and stigma loss its receptivity after 15:00.Nectarinia asiatica, N. zeylonica are the main pollinators. Autogamy, geitonogamy and xenogamy were carried out, to check whether the species is self compatible or not. Fruit set on self pollinated flowers, revealed that C. woodsonii is self compatible.