These are a native relative of the frangipani, and like their cousins they are deciduous & have sweetly perfumed flowers.
Commonly called “Banana Bush” from the resemblance of the fruits to tiny, waxy bananas, but beware! While a colourful name, it is also an unfortunate one, as these enticing little fruits are quite poisonous. However they do add a bright splash of colour to the dark of the understory.
Tabernaemontana, let’s call them “Windmill Bush”, live in drier rainforests ranging from Port Macquarie in NSW, up around the east & north coasts of Australia and into New Guinea and Timor.
While they can develop into small trees, locally they are most commonly found as shrubs less than two metres tall.
Some good places to find them around Brisbane are the dry rainforests in Upper Brookfield and Cedar Creek.