Brachychiton bidwillii is a highly variable species which may sometimes develop as a small tree on a single stem reaching 4-5 metres with a spread of 4 metres or so. However, other forms may be little over two metres tall. The Southern Queensland forms usually have deeply-lobed leaves, while the 'Maroochydore' form has very hairy, 5-lobed leaves which are purple-brown when young. This form has pink flowers of a different shape from all others, with a long tube. The largest flowers in the species are found in some plants from the northern inland (Leichhardt form).On the coast near Bowen is the completely different 'Northern Coastal' form, with deeply 5-lobed leaves, and smallish, bright red unfading flowers. It has a short but spectacular spring flowering period of 4-6 weeks. The Leichhardt forms flower for 3 months starting in mid-spring in cold years. In years with no frosts they can flower from July to February.