Flowering Ecology of the Species of the Genus Hypoxidia (Hypoxidaceae: Asparagales)

Abstract

Hypoxidia (Hypoxidaceae) is endemic to the Seychelles islands. The two species H. rhizophylla and H. maheensis have rarely been studied. The first studies of floral ecology are described based on 19 years of observations of cultivated (1992–1994) and wild (1998–2011) plants of H. rhizophylla and a single flowering event of cultivated H. maheensis. In H. rhizophylla, heavy rainfall acts as a trigger to flowering, with flowers opening 14 days after heavy rain. This can occur in any month and local rainfall can act as a trigger even in generally dry conditions. Flowers are only open for a few hours, usually in the morning. Pollinators have not been identified but only one specie has been seen visiting flowers regularly; the fly Dichaetomyia fasciculifera (Muscidae) is common on Silhouette island where 12% of flowers are pollinated but very scarce on Mahé where fruiting of H. rhizophylla is rarely recorded. Low rates of pollination and limited dispersal is thought to result in effective isolation of most populations which probably mainly reproduce clonally. Clarification of this requires further research into genetic structuring of the populations.