Pollination ecology and fruiting behaviour in a monoecious species, Jatropha curcas L. (Euphorbiaceae).

Jatropha curcas is a pantro pical shrub. It is monoecious and protandrous. The ratio of male to female flowers is 29 : 1. Both flower sexes open synchronously. The sexual system facilitates geitono gamy and xenogamy. The flower visitors include bees, ants, thrips and flies; bees and flies effect geitonogamy and xenogamy, while ants and thrips effect only geitonogamy. The fruiting behaviour indicates that the plant might selectively eliminate the growing offspring, e specially geitonogamous fruit to allocate the resources available to the plant, mostly for xenogamous fruit. The ability to self -pollinate through geitonogamy is considered to be adaptive for J. curcas for colonization. MONOECISM, the production of separate male and female flowers on the same plant, is relatively a common s exual system among flowering plants. It is widely prevalent in the members of Euphorbiaceae. Bullock 1 reported monoecy in the members of Euphorbia, Phyllanthus, Argythamnia, Chamaesyce, Cnidoscolus and Croton, and dioecy in Jatropha species. Studies made on the pollination ecology of some Euphorbiaceae species in Visakh apatnam region show that Cicca acida, Emblica officinalis 2