Gilbertiodendron dewevrei (abeum)
Gilbertiodendron dewevrei forest
Gilbertiodendron dewevrei (De Wild.) J.Léonard
abeum (Cameroon and Gabon); limbali (Congo); pauza (Angola); abeum à grandes feuilles (trade name for timber)
Not assessed according to IUCN Red List criteria, but this widespread species is likely to be of Least Concern (LC).
Lowland humid forest.
Timber and traditional medicine.
About this species
A large, evergreen tree of the African tropical humid forest, Gilbertiodendron dewevrei is an example of a species that can grow gregariously. That is to say, numerous individuals may grow together in the absence, or virtual absence, of large trees of any other species. Consequently, there are areas of forest in the Congo basin that are dominated by G. dewevrei, sometimes in almost pure stands. A handful of other tropical African forest trees from the pea and bean family (Leguminosae; Fabaceae sensu APG III 2009), such as Cynometra alexandri and Julbernardia seretii, share this tendency to form forests dominated by a single species.
Geography and distribution
Gilbertiodendron dewevrei is found in Angola, Cameroon, Central African Republic, Congo, Democratic Republic of Congo, Equatorial Guinea and Gabon.
A large tree of lowland humid African forest, Gilbertiodendron dewevrei is often found in swampy areas. Despite growing up to 45 m tall and 2 m in diameter, it does not have buttresses (woody fins at the base of the tree to help support it). The leaves are compound, with 2–5 pairs of leaflets and have conspicuous stipules (leaf-like appendages) at the base of the leaf stem. It is an evergreen species and replaces its leaves almost continuously throughout the year. The young leaf shoots are reddish-purple in colour.
The woody pods (fruits) are large (up to 30 cm long), flattened and covered in brown hairs. There is usually a single longitudinal nerve along the pod face near the upper margin. When pods open at maturity, they do so with explosive force. Nevertheless, because the seeds are large and heavy, they do not travel far. It has been estimated that populations of Gilbertiodendron dewevrei migrate only about 100 m every 200-300 years through successful seed dispersal and germination.
The wood is used in west-central Africa for construction work (such as boat-building) and other forms of carpentry such as making agricultural tools, furniture and toys. In traditional medicine, a decoction of the bark is used to treat diarrhoea and dysentery and to heal sores. The seeds are eaten in times of food shortage; they are also eaten by forest rodents, elephants and gorillas.
This species at Kew
Dried and alcohol-preserved specimens of Gilbertiodendron dewevrei are held in Kew’s Herbarium where they are available to researchers by appointment.
Specimens of the wood and bark are held in the Economic Botany Collection in the Sir Joseph Banks Building and are available to researchers by appointment.
Discoveries in Cameroon
During botanical inventory work in Cameroon, Kew botanist Xander van der Burgt noted that local tribesmen constructed umbrellas from the large juvenile leaves of this species, sewing the leaflets together with climbing stems from other plants. He also noted that their children made toys out of the large seeds.
Kew's work on this genus
The genus Gilbertiodendron is currently the subject of a taxonomic revision by Dr Manuel de la Estrella (University of Cordoba, Spain), and elements of the work are being carried out in collaboration with Kew botanists Barbara Mackinder and Xander van der Burgt. The latter is also leading a project looking at a related species, Gilbertiodendron ogoouense.
Angiosperm Phylogeny Group. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III. Botanical Journal of the Linnean Society 161: 105-121.
Blake, S. & Fay, M. (1997). Seed production by Gilbertiodendron dewevrei in the Nouabale-Ndoki National Park, Congo, and its implications for large mammals. Journal of Tropical Ecology 14: 885–891.
Burkill, H. M. (1995). The Useful Plants of West Tropical Africa. Edition 2. Vol. 3. Families J-L. Royal Botanic Gardens, Kew.
Lewis, G., Schrire, B., Mackinder, B. & Lock, M. (eds.) (2005). Legumes of the World. Royal Botanic Gardens, Kew.
Kew Science Editor: Barbara Mackinder
Kew contributors: Xander van der Burgt (photographs and field notes) and Steve Davis (Sustainable Uses Group)
Copyediting: Emma Tredwell
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