Forest coconut  (Voanioala gerardii)

Classified as Critically Endangered (CR) on the IUCN Red List (1).

The forest coconut is a relative of the well-known modern coconut, Cocos nucifera. It is a robust, solitary palm that can reach up to 20 metres tall and is anchored by a large root base (2). The trunk is characteristically 'stepped' and the feather-shaped leaves extending from the crown may reach up to 5 metres long (2). The waxy, green leaflets are fairly stiff, and around 70 are found on either side of the axis of each leaf (2). The fruits of this species are a rich red-brown colour when ripe (2) and grow in thick bunches at the crown (3). One of the remarkable features of this palm is the number of chromosomes its cells contains; at around 600 this is the highest number recorded for any monocotyledon (4).

Endemic to Madagascar, the forest coconut was first described and named in 1989 and is found only on the Masoala Peninsula in the northeast of the island (2). This palm is extremely rare and only 10 mature trees are currently known to exist (4).

Found in swampy valley bottoms or gentle slopes of primary rainforest (2).

The inner layer of the fruit is heavily thickened and deeply grooved, it is possible that this adaptation evolved in a similar way to the fruit of Satranala decussilvae, namely for dispersal by large birds or mammals such as the now extinct elephant bird (Aepyornis maximus) (2), or a giant lemur (4). Today, rotting fruits are found on the ground beneath mature trees suggesting that dispersal is ineffective, possibly due to the lack of these birds or mammals, which became extinct in the 17th Century (2).

Forest coconuts are cut down for their edible palm hearts and the seeds are also harvested for trade (4). Only 10 mature trees are known and such a small population is inherently vulnerable to any chance event that may occur. These trees are also vulnerable due to the current limited dispersal of their seeds (2).

The forest coconut is found within an area of the Masoala Peninsula that has recently been declared a National Park; the survival of the species will depend largely on the effectiveness of this park (4).