Vakwa parasol  (Martellidendron hornei)

The vakwa parasol is classified as Vulnerable (VU) on the IUCN Red List (1).

The elegant vakwa parasol (Martellidendron hornei) is a tree characterised by a smooth trunk which branches into threes, forming an umbrella-shaped crown of leaves (3). Pandanus species are known as the screw pines after the spiral arrangement of the leaves, which in this species are leathery, dark green and have edges armed with short, red spines. The leaves can grow up to an incredible 3.25 metres long and taper to fine points (2). The large fruit of the vakwa parasol (up to 30 centimetres across) hang on stalks from the tree and are made up of numerous drupes, packed tightly together. Each individual drupe is 14 centimetres long with an orange lower part and green upper part (2). Nearly all screw pines have stilt roots (4); roots that arise from the lower part of the trunk and bend down in a curve into the soil, so that the slender trunk appears to be standing on stilts. It is believed that these roots acts as props and support the tree, increasing its resistance to strong winds (5).

The vakwa parasol is found only in the Seychelles, where it occurs on the islands of Mahé, Silhouette, Praslin and Curieuse (3)

Once a dominant tree in palm forest, the vakwa parasol is now restricted to small areas of riverine forest (1). This tree is said to be a moisture-loving species (2).

It is generally thought that Pandanus species are pollinated by wind, although pollination by insects and other animals may also be likely. The fleshy drupes of Pandanus species are eaten by animals, which results in the seeds being excreted in a location away from the parent tree, but the dispersal of seeds by sea currents also occurs (6).

The clearance of mid-altitude forest in the Seychelles in the past is the primary cause behind the vakwa parasol’s decline (1). Today, however, the impact of invasive plants poses the greatest threat to the future of this species (1).

The vakwa parasol occurs in several national parks (1), including Vallée de Mai, a Natural World Heritage Site situated within Praslin National Park (7).

For further information on biodiversity and conservation in the Seychelles see:

• Nature Protection Trust of the Seychelles:
  http://islandbiodiversity.com
• Nature Seychelles:
  http://www.natureseychelles.org