St Helena boxwood (Mellissia begonifolia)

GenusMellissia (1)
SizeHeight: 1 - 2 m (2)

Classified as Critically Endangered (CR) on the IUCN Red List (5).

The St Helena boxwood is yet another of the endemic flora of this remote island that is teetering on the brink of extinction. This small shrub has many twisted and zigzag branches and smells strongly of tobacco (2). The tapered heart-shaped leaves are soft, and single white flowers are held on drooping stalks hidden amongst the foliage (2). Small berries are produced (2).

Endemic to St Helena in the southern Atlantic Ocean, the boxwood was previously widespread in the southeastern region of the island, and was known from areas such as Long Range, Stone Tops and Boxwood Hill (2). The species was first discovered in 1805, but by 1875 it was already rare and was thought to be extinct by the turn of the century (3). Miraculously, a single specimen was rediscovered in November 1998 and although it was close to death from an infestation of mealy bugs, 400 seeds were collected for possible propagation (3). A further six wild specimens were discovered in 2001 and (as of April 2003) the wild population numbered 16 individuals (5). However, only one of these can be considered to be mature and this individual has supplied most of the seeds for cultivated populations (5). Cultivated plants are held at the Royal Botanic Gardens, Kew, the Royal Horticultural Society at Wisley in the UK (3), and on St Helena itself at the Environmental Conservation Section Nursery at Scotland (5).

The St Helena boxwood has been reported as being a native of rocky hills (2).

The flowering time is December (2).

The island of St Helena has suffered over 450 years of human exploitation and has come to symbolise the environmental collapse of the world's oceanic islands. Today the landscape is altered beyond recognition and many of the endemic and unique species have been lost for ever (4). The introduction of goats and other livestock as well as the clearing of native forests for timber have ravaged the island; 60 percent of St Helena became barren ground known as the Crown Wastes following massive soil erosion (4). The St Helena boxwood appears to contain toxins that prevented it from being damaged by goats and therefore widespread erosion is likely to have been the main cause of its disappearance from the island (2).

Today all that survives of the St Helena boxwood are a precarious wild population and around 50 cultivated plants, many situated at the Royal Botanic Gardens, Kew in the UK (3). It is hoped that some of these will be returned to St Helena and re-introduced to the wild, however, early attempts at re-introduction have not proven successful and there is a lack of expertise on the island itself (3). Recent studies have revealed that there is no genetic variation amongst the remaining plants of this species, providing a further predicament to the conservation drive, as individuals will be less adaptable and more likely to succumb to pests (3).

For more information on St Helena see:

Authenticated (30/6/03) by Rebecca Cairns-Wicks. Chair, IUCN SSC South Atlantic Island Plant Specialist Group.

  1. IUCN Red List (April, 2011)