Floral Ontogeny of the Jackfruit, Artocarpus heterophyllus Lam. (Moraceae)

Scanning electron micrographs of the jackfruit are presented, showing the development of the male and female inflorescences. An unusual feature is that the perianth segments in the female fuse in the middle region after anthesis. Primordia numbers decreased from 315 per mm2 at floral initiation to 0.26 per mm2 by completion of anthesis. At anthesis the males rotted before abscission, emitting a smell of overripe fruit which attracted large numbers of insects. No insects visited the females. Pollen was not shed readily after light physical disturbance, as would be expected from a wind-pollinated species. These results are discussed in the light of conflicting views of whether anemophily or entomophily is the basic mode of pollination.