Black Bean Tree (Castanospermum australe) Leaves,flowers and fruits.

Black Bean Tree - Castanospermum australe

Castanospermum is a monotypic genus in the legume family Fabaceae. The sole species is Castanospermum australe, commonly known as Moreton Bay chestnut or black bean, which is native to rainforested areas on the east coast of Queensland and northeastern New South Wales, and to the southwest Pacific islands of Vanuatu and New Caledonia.

Castanospermum australe is a tropical, arge evergreen tree of about 18-35 m tall,  though commonly much smalle, and 5-12 m width with an erect trunk, grey to brown smooth bark, and glossy dark green leaves.  The leaves are 15 cm (5.9 in) long and 6–7 cm broad, pinnate, with 11-15 leaflets.The flowers are pea-shaped, yellow to orange in colour and form into clusters.

The fruit is a cylindrical pod 12–20 cm  long and 4–6 cm diameter, the interior divided by a spongy substance into one to five cells, each of which contains a large chestnut-like seed, 3 - 4.5cm wide. The seed is edible when cooked but requires extensive leaching prior to consumption due to its high saponins content.

Due to its significance as a food for Aboriginal people, blackbean trees were spread by hand into mountain areas on the east coast of Australia. All the trees in New South Wales are descended from a single seed. The plant naturally spreads by water. It has been introduced to India, Malaysia, Papua New Guinea, Sri Lanka, South Africa and the United States of America.

Due to its importance as a food, the blackbean tree was a seasonal gathering point for Aboriginal peoples, and this acted as a catalyst for ceremonies. Songlines featuring the black bean seeds have been collected. The bark fibre has been used for fish and animal traps, nets and baskets, and the empty seed pods have been used as toy boats. Additionally, the tree has been used as a seasonal signal for when to hunt jungle fowl.

The unprocessed seeds are poisonous since they contain toxic saponins, and can cause vomiting and diarrhoea, but they become edible when carefully prepared. The Australian aborigines finely sliced the seeds and soaked them in running water for 10 days before roasting them and grinding them into a powder. This powder could be stored for later use. The seeds have been prepared and eaten for at least 2,500 years.  The cooked seed tastes like a sweet chestnut.

The seed yields compounds called castanospermine that are under investigation as HIV inhibitors and might be useful in the treatment of AIDS. Parts of the tree contain chemicals which, after careful extraction, have been shown to have anti-cancer, anti-inflammatory, and anti-HIV properties.

The trees are popular as potted plants in Asia, Europe and America. In addition, they have been used as shade trees in landscaping for parks.

The wood was used by Aboriginal people for spear-throwers.  The wood can be used as a fuel. The timber, which somewhat resembles walnut, is soft, fine-grained, and takes a good polish, and the wood has a durability rating above-ground of over 40 years longevity.  Used in construction, cabinet making, carving etc. One of the most valuable woods in Australia, the sliced veneers can be good substitute for teak. The wood has a density of 700 kg /cu m.

Source:
https://en.wikipedia.org/wiki/Castanospermum
https://pfaf.org/user/Plant.aspx?LatinName=Castanospermum+australe