Madagascar screwpine

The approximately 700 species of screw pines inhabit marshy habitats in the rainforest and in coastal regions near the sea. They are also frequently referred to as pandanus or screw palms. Pandanus is derived from their scientific name, Pandanaceae, whereas the term ‘screw palm’ is misleading, as the plant is not related to palms. Some species of the tree-like screw pines form tuft-like clusters of leaves in the upper and outer regions of their branches.

The leathery, spiny leaves can grow up to nine metres long in large species. The leaves are arranged in three spirally twisted rows, which is why this family of plants is known as the screw pine family.

Screw-tree plants are generally unisexual, meaning there are male and female plants. At the base of the inflorescences, sugar-rich, fleshy leaves develop, which serve as a food source for birds, bats and fruit bats. These animals carry out pollination in many species. Some species are pollinated by the wind, whilst others reproduce vegetatively. Small lateral branches fall to the ground, take root and grow into independent plants.

Screw pines are used for commercial purposes. For example, the Madagascan species Pandanus utilis is cultivated in the Caribbean and Central America to provide material for weaving. The leaves are used to make coffee sacks, baskets, household items and roofing. A starchy food is obtained from the fruits of the female plant by boiling them. The pleasant scent of the male spikes acts as an aphrodisiac. The tips of the stilt roots are made into brushes, and the decoction extracted from the roots is said to cure sexually transmitted diseases.