It is a vigorous, tender evergreen perennial climber with nodding red flowers, each surrounded by white and purple filaments.

It has smooth, cordate, ovate or acuminate leaves; petioles bearing from 4 to 6 glands; an emetic and narcotic root; scented flowers; and a large, oblong fruit, up to 12 inches (30 cm) in length.

P. laurifolia is the water lemon and P. maliformis the sweet calabash of the West Indies.

In some parts of Sri Lanka the fruit, where it is known as ටං ටිං ([tʌŋ tIŋ]), රට පුහුල් or ටුං ටුං,[5] is cooked as a vegetable curry, and the seeds are consumed as a snack or used to extract juice.

Requiring a minimum temperature of 8 °C (46 °F), in temperate zones it must be grown under glass.