The Calabash Tree is not a common tree in Singapore. The place that I can recall seeing this tree is in the National Orchid Gardens in the Singapore Botanic Gardens. I vaguely remember seeing some planted amongst some bromeliads near the vicinity of Yuen-Peng McNeice Bromeliad Collection.
Although the appearance of its large fruits are gourd-like, it is not a member of the melon or gourd family, Cucurbitaceae. Instead, it is classified in the Bignoniaceae family, where the once common African Tulip Tree and currently a very popular ornamental shrub, Yellow Bells, belong to. Its exact origins is not known and today can be found growing throughout the Caribbean, Mexico, Central America, and northern South America. It has been introduced throughout the tropics.
Scientifically known as Crescentia cujete, the Calabash Tree grows as an evergreen tree can attain a height of 10 m. It features a broad but irregular crown comprised long, spreading and arching branches which is capable of providing dappled shade on sunny days. Leaves are simple and elliptical in shape clustered at the nodes. As a result of this growth habit, this tree often becomes a surrogate for orchid-growers to perch their plants on its branches. Crescentia cujete is grown in lawns and parks, and used for hedges.
This tree produces greenish-yellow flowers marked with purple veins on the trunk or main branches. Flowers are reported to open in the evening and emit a slight odour. They close and wither away by afternoon time. The oval, gourd-like fruit has a hard and woody rind and can grow up to 25 cm in diameter. Each fruit takes up to seven months to ripen. Ripened fruits are brown in colour and the seeds inside are surrounded by light-colorud pulp. The shell of the dried fruits is used to make a wide range of household utensils or filled with sand to make musical instruments. The larger fruits are used as bowls or made into helmets that are worn by bird hunters.
The fruits are not eaten as a dessert fruit but have medicinal properties. From Plant Resources of South East Asia (PROSEA), the fresh fruit pulp is documented to be macerated in water and is considered depurative, cooling and a febrifuge and good for headache and burns in West Africa and the Caribbean. In Vietnamese folk medicine, the dried fruit is used as an expectorant, antitussive, laxative and stomachic. In West Africa, the ash of the roasted fruit is considered mildly purgative and diuretic. In Central America, various parts of the fruit are a common ingredient in syrups for cough and colds.
Other parts of the tree are also used medicinally. In Sumatra, a decoction of the bark is used to clean wounds, and the pounded leaves are applied as a poultice for headache. In Thailand and Central America, crushed leaves are applied on wounds to stop bleeding and promote healing. A decoction of the leaves or bark is astringent and taken for diarrhoea and dysentery.
Wood from this tree has a range of uses which include manufacture of cattle yokes, tool handles, wooden wheels, ribs in boat building and thin strips are used to make baskets and hampers.
Crescentia cujete is easily confused with another related species, Crescentia alata. The latter has a more upright form, with much fewer criss-crossing branches, and possesses smaller fruits and trifoliate leaves.