In message , Richard Wright
writes
This small tree grows along roadsides close to the bank of the Colo
river west of Sydney. This is a warm temperate zone, with good
rainfall.

http://www.box.net/shared/static/mm49y5789h.jpg

It has fruits containing nuts.

The internal structure of the fruit looks something like a mangosteen,
but the thin pulp has an astringent flavour.

Inside the the thin shell is a pure white nut. It tastes pleasantly
mealy, but not delicious. I spat it out in case it is poisonous.

I don't think it is a native Australian species. There are a lot of
garden escapes in this area.

Since you've now identified it as Thespesia populnea, it's not listed as
native to New South Wales. However it might be native to Queensland. (T.
populnea occurs in coastal locations over much of the tropics, but
there's also confusion with T. populneoides.)

(The reference I had for T. populnea being present in Queensland - the
Millenium Seed Bank target list - seems to have disappeared from the
face of the web.)

What species is it?

--
Stewart Robert Hinsley
http://www.malvaceae.info/Biology/Bi.../Australia.php