Northia  (Northia hornei)

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).

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

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).

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).

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 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).

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

• Nature Protection Trust of the Seychelles:
  http://members.aol.com/jstgerlach
• Nature Seychelles:
  http://www.natureseychelles.org

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk