Phytogeography, biology and conservation of Western Australian Epacridaceae

The Epacridaceae of Western Australia comprise 181 named species distributed in 17 genera. One hundred and seventy seven species (98 % of the total) and ten genera are endemic to the region. Within Western Australia, all members are confined to the south, with a bimodal pattern of species diversity centred on the sandplains and uplands around the Stirling Ranges and Mount Lesueur. Leucopogon, the largest genus, reflects this pattern, however, species diversity is greatest on the south coastal sandplains. All species are woody shrubs, mostly found on neutral or acidic sandy soils. Plants of al least 120 species are killed by fire; Astroloma contains the only significant number of resprouting species. Although some species are in flower every month every year, autumn/winter flowering is a common feature of many members of the family. All species are biotically pollinated. Bird pollination is found in 18 species in six genera. The remaining species are insect pollinated. Bees are the major pollinators in Leucopagon, Conostephium and Coleanthera. Moths and butterflies are important pollinators in Andersonia, Leucopogon, Lysinema and Styphelia. Flies are minor pollinators of some species of Andersonia, Leucopogon and Monotoca. All species studied are protandrous and outbreeding, with only Cosmelia being capable of self pollination. Fruits are fleshy in Astroloma, Brachyloma, Croninia, in certain species of Leucopogon and Styphelia and are animal dispersed. Other genera have dry, dehiscent fruit with gravity or wind dispersed seeds. Many species have relatively narrow distribution ranges, 90 species having ranges of over 300 km, 54 species have ranges of 100-300 km and 37 have ranges of less than 100 km (and there are many undescribed species in this group). The conservation status of many species is still poorly known. Dieback disease is a major threat to the family, and could cause the extinction of several species in the wild. (C) 1996 Annals of Botany Company