Within the Kings Park bushland, three major plant communities are supported - limestone heathland; Banksia woodland with B. attenuata, B. grandis, B. menziesii and B. prionotes; and low moist areas with Banksia ilicifolia. Prior to European settlement, the Kings Park bushland would have been dominated by tall Tuart (Eucalyptus gomphocephala), Jarrah (Eucalyptus marginata) and Marri (Corymbia callophylla) with Banksia species and Allocasuarina fraseriana sub-dominating.
Today the woodlands are often dominated by Banksia species and Allocasuarina fraseriana. There are 326 species of local native plants growing in the bushland, which represents about 15% of the native flora of the Perth Region. Of particular importance is the limestone escarpment. Only three relatively large areas of cliff-side vegetation, Kings Park, Blackwall Reach and Mt Henry can now be found along the Swan River. The mixed closed heaths of the escarpment contain a diverse and unique assemblage of shrubs, herbs, sedges and grasses normally associated with limestone heaths of nearer coastal areas. The mixed closed heaths in Kings Park are one of the most inland occurrences of these estuarine cliff communities and are contiguous with adjacent bushland areas.
In addition to the bushland flora, the Western Australian Botanic Garden is located within Kings Park and is primarily dedicated to the conservation, cultivation, display and interpretation of the state’s native flora. Approximately 3,000 taxa of native plants are on display, promoting community appreciation and understanding of the flora and the importance of its conservation in the wild.