AbstractThe aquatic vegetation of three sites on the Atherton Tableland is described and analysed with the aid of numerical classifications. Despite major physiognomic differences in the vegetation between sites, four floristic groups are recognized which can be related to major habitat types. Water depth and seasonal fluctuations in water level are suggested as the main factors controlling vegetation distributions in the absence of disturbance by biotic agencies. Species characteristic of particular aquatic communities are identified and these could prove useful in the recognition of hydroseral stages in pollen diagrams constructed from these sites and in the determination of past lake levels.