Australian chestnuts? The fruit at the base of the Castanospermum resemble chestnuts. That makes the slender stems of this miniature tropical tree extra decorative. But watch out! The fruit is toxic. The Australian chestnut loves a warm environment, ideally between 18 and 25 degrees. Water weekly in the summer and once every two weeks in the winter. Allow the soil to become almost completely dry before watering it again. Preferably, pour the water in its tray. The plant does like light, but not strong, midday sunshine. The chestnut loves morning and evening sun. The plant can tolerate high humidity, so a bathroom is also a fine place for it.