For the identification of insects and other fauna and flora of South Africa: please click on the following links:
Insects and related species: Antlions - Ants - Bees - Beetles - Bugs - Butterflies, Moths and Caterpillars - Centipedes and Millipedes - Cockroaches - Crickets - Dragonflies and Damselflies - Grasshoppers and Katydids - Mantis - Stick Insects - Ticks and Mites - Wasps - Woodlice
Plants, Trees, Flowers: (Note: Unless plants fall into a specific species such as Cacti, they have been classified by their flower colour to make them easier to find) Bonsai - Cacti, Succulents, Aloes, Euplorbia - Ferns and Cycads - Flowers - Fungi, Lichen and Moss - Grass - Trees
Animals, Birds, Reptiles etc.: Animals, Birds, Fish and Crabs - Frogs - Lizards - Scorpions - Snails and Slugs - Snakes - Spiders - Tortoise, Turtles and Terrapins - Whipscorpions
Other photography: Aeroplanes - Cars and Bikes - Travel - Sunrise - Water drops/falls - Sudwala and Sterkfontein Caves etc.

Tuesday, November 26, 2013

Common Screwpine (Pandanus utilis)

Family Pandanaceae  
 Despite its name, a tropical tree and not a pine. It is not endemic to South Africa. Pandanus utilis is a palm-like evergreen tree, ranging in height up to 20 metres (66 ft). They are found in tropical areas and have an upright trunk that is smooth with many horizontal spreading branches with annular leaf scars. Old leaf scars spiral around the branches and trunk, like a screw.
 As with other member of the genus Pandanus, P. utilis lacks secondary growth. The secondary growth of most trees is the production of wood to aid in support of the trunk. Without this supportive structure, the P. utilis grows many pale brown prop roots at the base of the trunk. These adventitious roots arise from the stem above the soil level and help support the plant. These roots not only anchor the tree but also keep it upright during times of heavy winds and rain in tropical regions. Prop roots can be 2.5 to 7.5 centimetres (0.98 to 3.0 in) in diameter.
 P. utilis is dioecious, with the female and male reproducing structures occurring on different plants. Individual plants are either male producing microspores or female producing megaspores. This plant being unisexual allows it to cross-fertilize with other screwpines. The male plants produce fragrant colorful flowers in long spikes. These long spikes are with 8–12 stamens inserted pseudo-umbellately on slender columns 10 to 15 millimetres (0.39 to 0.59 in) long. The female plants produce fruits resembling pineapples or oversized pine cones changing from green to yellow/orange when ripe. The female structure has a 3–8 celled ovary crowned by a sessile stigma.
 P. utilis grows well near the sea, being salt-tolerant. It is a strictly tropical tree that will not survive frost. It grows in full sun to partial shade. Seeds take two to three months to germinate.
 The screw pine has been shown to have many uses. In coastal areas, it has been used for erosion control due to its numerous aerial roots. These roots help bind the sand dunes along the coast from eroding water and wind. The leaves of P. utilis are used in different cultures for thatching and the production of numerous materials. In areas like Madagascar, Réunion and Mauritius, the leaves are used to make ropes, baskets, mats, hats, place mats, nets, thatched roofs for homes and even paper. The waxy covering over the leaves makes them especially attractive for baskets and roofs with their natural water-resistant surface. The fruits form a starchy food and can be eaten after cooked.