Screw pine can refer to any tree of the genus Pandanus, of which there are approximately 600 species. In common usage, however, screw pine generally refers to the Pandanas utilis, a tropical tree recognizable by its distinctive-looking fruit, its screw-like trunk and branch markings, and its network of prop roots. Its long, serrated leaves are used by some cultures to make roofing, mats, and baskets.
The screw pine thrives in tropical climates, and accordingly it is most often found in Southeast Asia, parts of Africa, and southern Florida. It generally cannot survive in temperatures lower than 55 degrees Fahrenheit (12.78 degrees Celsius). The tree is also very tolerant of salty soil and air, making it a good choice for seaside gardens in tropical regions.
There are several distinguishing features which make the screw pine easily recognizable. First of all, its trunk and branches show spiral markings — similar in appearance to the shaft of a screw — which are actually scars left behind by leaves which have fallen away. This characteristic is the source of the tree’s name.
Secondly, the screw pine usually has a network of prop roots which resemble a cluster of stilts that lean from the tree’s trunk into the soil. Sometimes these roots create the illusion that the body of the tree is floating above the ground. Often, the horizontal extension of the screw pine’s branches is greater than its overall height, making it quite top heavy. The function of these prop roots is to create extra support which balances out this top-heaviness and keeps the tree rooted firmly in the soil.
Another distinct feature of the screw pine is its fruit, which is bright orange in color and resembles something like a cross between a pinecone and a pineapple. This fruit is a favorite meal of animals like bats, raccoons, and lizards. Although the fruits of certain Pandanus species are frequently used in Southeast Asian cuisine, that of Pandanus utilis, while technically edible once cooked, is generally enjoyed only by animals.
Long, tough leaves grow from the screw pine’s branches in a spiral formation. The edges of these leaves are serrated with small, sharp teeth that can scratch or cut human skin when handled carelessly. They are coated with a natural wax which gives them waterproof qualities, and in some cultures, they are dried and woven into water-resistant thatch roofing. These leaves are also sometimes used to make handicrafts such as baskets and mats.