Wet heathlands, formed by sclerophyllous nanophanerophytes and graminoids growing on seasonally waterlogged soil, were surveyed on the southern Swan Coastal Plain and classified using TWINSPAN. Three main wet heathland groups were identified: the Pericalymma- Hypocalymma, Pericalymma-Regelia and Melaleuca-Cassytha alliances respectively. The Pericalymma-Hypocalymma alliance is found north of the Capel River in depressions in the Bassendean Dune system on colluvial sands. The Pericalymma-Regelia alliance is found south of the Capel River primarily on colluvial wet sands, and shallow sands and loams. The Melaleuca-Cassytha alliance was found north of the Capel River mainly on heavy clays. These heathlands were species poor compared to Australian dry heathlands, with the number of species per 100 m2 ranging from 9 to 26. The ecology of these heathlands is discussed
