Flower-of-an-hour, Bladder Ketmia
This species has been recently revised, and split into three species, all native to Australia. Two of these species, Hibiscus tridactylites and Hibiscus verdcourtii, could occur in the area covered by this key.
Description and photos of Hibiscus tridactylites and Hibiscus verdcourtii in Craven, L.A., de Lange, P.J., Lally, T.R., Murray, B.G. & Johnson, S.B., (2011) A taxonomic re-evaluation of Hibiscus trionum (Malvaceae) in Australasia. New Zealand Journal of Botany 49(1): 27-37