Endemics of St Helena - Bastard Gumwood

 

BASTARD GUMWOOD

 

Common name: Bastard Gumwood

Scientific name:Commidendrum rotundifolium

IUCN status: Extinct in the wild

 

 

Natural History

A single Bastard Gumwood was known to grow at Black Field, Longwood in 1868. After the death of this tree, the species was thought to have become extinct. However, in 1982 another single tree was discovered by Stedson Stroud and identified by George Benjamin.

This tree was growing ouf of a cliff close to Horse Pasture. This tree died in August 1986, but, fortunately, not before a cutting and seedlings had been successfully raised at the Endemic Nursery.

Only a single cutting of the tree was succesful and this was planted at Pounceys in 1983. This cutting died about 1992. The seedlings raised from the tree were also planted in Pounceys. Today, 19 survive. These are all that is left of the whole species of Bastards Gumwoods.

DESCRIPTION

This tree is very similar to the Gumwood (Commidendrum robustum). Smaller in height, all the trees known today are not taller than three metres and have weak growth. The leaves are of a mid green colour and are about 50-70mm in length. Flowering begins in March/April and continues through to May/June. The flowering heads form in clusters between the leaves near to the ends of the branches. They are whitish turning brown with age.

NUMBER OF SURVIVING POPULATIONS

The Bastard Gumwood is extinct in the wild. That is, the only surviving individuals of the species are growing in a place where they have been planted deliberately and have not arrived there naturally. There is only one major planting of this species, a total of 10 mature trees at Pounceys. These are all seedlings from the last tree at Horse Pasture.

CONSERVATION RECOVERY PROGRAMMES

In recent years, the E.C.S. has found it difficult to get seed collected from the trees at Pounceys to germinate and have also failed to get cuttings to root. This is a serious problem which must be overcome if we are to prevent the extinction of this species.

To try and improve the quality of material used for cuttings, the area around the trees is weeded and mulched regularly in the hope that this will encourage healthy new shoots.

The failure to produce viable seed is more serious. There may be several reasons for this related to the fact that this species has become so rare. Research needs to be carried out to study the flowers and the pollination/fertilization process. A student from Edinburgh Botanic Garden, under the supervision of Quentin Cronk, has been studying the fruit and flowers of all the Gumwoods. It is hoped that this research may give us some clues to why no viable seed is being set in the Bastard Gumwood.