Northia

Little information is available on the biology of Northia hornei. The flowers are bisexual, that is, contain both male and female reproductive parts (stamens and pistils) (2). It has been reported that fruit bats disperse the seeds of Northia hornei (5), but they are apparently not well dispersed, as many seedlings and saplings are found in clusters under a parent tree (6). The large size of the seeds may be an adaptation to limit the number of animals that are capable of dispersing them, to reduce the chance of the seeds being dropped into the sea by the animal; a very real risk for plants on small islands. Instead, the seeds of Northia hornei may fall from the tree and germinate close to the parent plant (2). Northia hornei trees play an important role in the forest ecosystem of the Seychelles, with old trees supporting a diversity of epiphytic plants, and dead and decaying trees providing saprophytes with critical habitat (5).

Northia hornei occurs in Morne Seychelloise National Park on Mahé Island (1), where regular monitoring of this species has been undertaken (6). The seedlings of this tree are also being used in a reforestation programme (1).

A gnarled tree with reddish-brown bark, Northia hornei can grow up to twenty metres tall amongst the shelter of forests, but may be less than three metres tall when growing in more exposed areas (2). Large, leathery leaves, measuring up to 30 centimetres in length, cluster together in a spiral arrangement at the end of shoots. The upper surface of each leaf is dark green, while the under surface is rust-coloured and has a felt-like touch due to the dense covering of short, soft hairs (2). Like other trees in the Sapotaceae family, Northia hornei produces a milky white sap, known as latex (3). Clusters of five to ten greenish-white, musky-scented flowers droop from short stalks, from where the leafstalk joins the stem (2) (4). Each fleshy, spherical fruit, measuring up to ten centimetres wide, contains a single, large seed. The chestnut brown seed, up to eight centimetres long, is smooth and shiny on one side and wrinkled on the other, resembling a capucin monk's face in his hood, hence this tree's common name 'capucin' (2) (4).

Northia hornei is a common tree in the forests of the islands on which occurs (1), and is the dominant species in some of the forests above 600 metres (2).

Occurs only in the Seychelles, on the islands of Mahé, Praslin, Silhouette, Curieuse and Felicite (1).

Classified as Vulnerable (VU) on the IUCN Red List (1).

Until recently, Northia hornei was exploited for its timber (2) (5). The first settlers of the Seychelles exported Northia from Mahé to Mauritius, where it was used for roofing shingles and cartwheel spokes, and in the 1950s, Northia was extensively logged on Silhouette for construction on Mahé (2). Today, the main threat to populations of Northia hornei is said to come from the invasion of introduced plants (1).

Northia is a genus of plants in the family Sapotaceae.

The name was first published by Joseph Dalton Hooker, in Hooker's Icones Plantarum (Sep 1884), in his description of Northia seychellana. The spelling was given as Northia on the plate, but the variant Northea in the text. Hooker gave the genus name in honour of the botanical illustrator and painter, Marianne North. Perhaps its most notable characteristic is the huge size of its seeds, each up to 3.1 inches (eight centimeters) in length, and nearly as wide.

Northia seychellana is the only species accepted in the genus. It is endemic to the Seychelles Islands. A few other species were formerly included in Northia but have been moved to Manilkara:

Formerly included Northia fasciculata - Manilkara fasciculata - Indonesia, Philippines, New Guinea Northia hoshinoi - Manilkara hoshinoi - Pohnpei Northia vitiensis - Manilkara vitiensis - Fiji