Castanospermum australe (Moreton Bay Chestnut or Blackbean), the only species in the genus Castanospermum, is a flowering plant in the family Fabaceae, native to the east coast of Australia in Queensland and New South Wales, and to Vanuatu and New Caledonia.
It is a large evergreen tree
growing to 40 m tall, though commonly much smaller. The leaves
are 15 cm long and 6-7 cm broad, pinnate
, with 11-15 leaflets. The flowers
are bicoloured red and yellow, 3-4 cm long, produced in racemes
6 cm long. The fruit
is a cylindrical pod
12-20 cm long and 4-6 cm diameter, the interior divided by a spongy substance into three to five cells, each of which contains a large chestnut
The seeds are poisonous, but become edible when carefully prepared by pounding into flour, leaching with water, and roasting. The timber
, which somewhat resembles walnut
, is soft, fine-grained, and takes a good polish, but is not durable.