Australian Chestnut (Castanospermum)
Castanospermum australe, 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 the Pacific islands of Vanuatu, New Caledonia, and the island of New Britain.
Let the soil be slightly dry in between watering.
WAyer your Australian Chestnut once a week. Wait until the top of the soil has dried out and then give him a good drink. Always remove your plant from the outer pot when you water, and do not put return it to the ceramic pot until it's stopped dripping. This should save you from overwatering.