Moreton Bay Chestnut
Castanospermum australe
Family: Fabaceae
What it is like
An evergreen tree up to 18-35 m tall. It spreads to 5-12 m across. The stem is erect and stout. The bark is grey to brown and smooth. The leaves are glossy dark green. The leaves are 30-45 cm long. Leaves have 11-15 leaflets. These are slightly curved. The leaflets are 7-12 cm long by 2-5 cm wide. The leaves or cut bark have a cucumber like smell. Flowers are in clusters 5-15 cm long on old wood. They are yellow to orange. The flowers are pea shaped and grow one after another along a stalk in dense clusters. The fruit are broad, bean-like pods. The pods are up to 20 cm long and thick. They can be 4-6 cm wide and woody. Inside the pods, the seeds are in a white pith. There are 1-5 seeds in a pod. The seeds are large and starchy with a shiny brown coat. They are 3-5 cm long.
The timber is a very useful cabinet wood. There is only one Castanospermum species.
Where it is found
A tropical plant. Introduced and grown along the coast in Papua New Guinea in some areas. It suits rainforest and creek bank sites. It suits humid locations. It needs light, well drained soil in a protected sunny position. It is drought and frost tender and is damaged by wind. Trees need a temperature above 7°C but can stand very short periods down to 0°C. They are best with a mean annual temperature of 28°C. It suits warm temperate to tropical regions. In Melbourne Botanical Gardens. It suits hardiness zones 10-12.
Countries/locations it is found in
Africa, Asia, Australia, Central America, East Africa, Fiji, Hawaii, India, Indonesia, Kenya, New Caledonia, Malaysia, Mozambique, Myanmar, Norfolk Island, Pacific, Pakistan, Papua New Guinea, SE Asia, Slovenia, Solomon Islands, Southern Africa, Sri Lanka, USA, Vanuatu, West Indies, Zimbabwe
How it is used for food
The seeds are eaten after extensive processing (They are soaked for 10 days, pounded and baked.) They may still contain some poison. CAUTION In Australia several deaths and stomach upsets have been reported in cattle which have eaten the seeds.
The tree is introduced to Papua New Guinea and may not be much used for food.
Edible parts
Seeds kernel, nuts, caution
How it is grown
It grows from seeds which often commence germinating while still in the pod on the ground. Seeds germinate very easily. They germinate in 2-4 weeks. Seed need to be sown when the temperature is at least 13-18°C.
In Australia fruit are produced from March to November.
Its other names
Local names
Australian chestnut, Avstralski kostanj, Bean tree, Black bean, Huhuboi, Thawka-mala, Wuhbo