Yes it must be Hibiscus Radiatus....I have wondered for 20 years....thanks for the replies. In my climate ( Monsoonal Wet/Dry ) I treat the plant as an annual, although if given copious quantities of water during the 'dry' it will survive until the rains return.
Potted specimens I grew at Yandicoogina, Western Australia ( Pilbara hot arid desert summer temps +45c )
