Pandanus

(screw pines), a genus of monocotyledonous plants of the family Pandanaceae. The plants are treelike and have branched trunks that reach heights of 10–15 m (occasionally 25 m). Adventitious roots grow from the lower part of the trunk and from the branches. Sometimes the lower part of the trunk dies, and the plant is supported by its stilt-like roots. The stiff, linear leaves are 3–4 m long and 10–15 cm wide; they are arranged in two to four spiral rows. The plants are dioecious, and their unisexual flowers are gathered into spadices or, less commonly, panicles. Perianths are absent. The fruits are berries or drupes, which often are somewhat woody and gathered into an aggregate.

There are about 600 species of screw pines, distributed mainly in the tropics of the eastern hemisphere. They grow on seacoasts, along rivers, and in tropical rain forests. Some species, including P. tectorius, P. utilis, and P. fragrans, are cultivated in the tropics for their edible fruits and fibrous leaves. The leaves are used to weave various articles and are processed into industrial fabrics, brushes, and ropes. A number of species, such as P. utilis, are cultivated as ornamentals in greenhouses and homes.