Notes on the Natural History of Cycas seemannii (Cycadaceae)

Cycas seemannii occurs in several habitats in Vanuatu, New Caledonia, Fiji and Tonga, but is mostly coastal. Growth rates are about 5-15cm.yr-1 and sex ratios observed were almost neutral. Mechanisms to survive in adverse environments are discussed. Female plants were found to produce, on average, longer leaves with more leaflets than male plants. Larvae of an unidentified moth, which are parasitised by at least two species of wasps, mine the leaflets of C. seemannii. Reproduction occurs mainly by seeds and bulbils. Wind appears to be the major pollination agent. Seed dispersal, other than oceanic, appears to be inefficient.