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

Legumes are plants in the family Fabaceae, or the fruit or seeds of such plants. When used as a dry grain for human consumption, the seeds are also called pulses. Legumes are grown agriculturally, primarily for human consumption; for livestock forage and silage; and as soil-enhancing green manure. Well-known legumes include beans, soybeans, chickpeas, peanuts, lentils, lupins, grass peas, mesquite, carob, tamarind, alfalfa, and clover. Legumes produce a botanically unique type of fruit – a simple dry fruit that develops from a simple carpel and usually dehisces on two sides.