Irvingia gabonensis
Tree 10-40 m tall; buttresses to 3 m high; bole straight and unbranched (in wild trees); crown approximately spherical or taller than wide; foliage dense and dark green. Leavese lliptic; apex tapering or occasionally with a barely discernable acute acumen; base acute to cuneate; length 4.5-8 cm, width 2-4 cm (canopy leaves from mature wild trees); secondary, tertiary and quaternary vena-tion obvious, areolaeg reater than 1 mm diam. Inflorescenceax illary, laxly branched panicle to 9 cm long. Flowers in fascicles; pedicels to 5 mm long; sepals 1-1.5 mm; petals yellowish white, 3-4 mm long; filaments 4-5 mm long. Fruit ellipsoid to cylindrical, occasionally almost spherical, only slightly laterally compressed; length 4-6.5 cm, width 4.2-6.4, thickness 3.4-6 cm; smooth; green when ripe; mesocarp bright orange, soft and juicy when ripe with a few weak fibres, fibres appressed and curly, or absent on old pyrenes; taste of mesocarp from sweet to slightly bitter with a turpentine flavour but always edible; pyrene single, woody but usually disintegrating after one season on the ground. Seeds 2.5-3.8 cm long, 1.7-2.7 cm wide, 0.8-1.2 cm thick; endosperm visible on fresh material as a white dot 2-3 mm diam. on the inside of the testa opposite the point of attachment of the two cotyledons, this sometimes extends to form a white streak 1-2 mm broad, running parallel to the axis of each cotyledon, on the inside of the testa.
Source: Harris D.J. 1996. A Revision of the Irvingiaceae in Africa. Bulletin du Jardin botanique national de Belgique 65: 143-196.
Common
This species occurs in the wild in forest on dry land. Two or three mature trees often occur together and in some areas it is reported to be gregarious. Since this species is cultivated the high densities in what appears to be natural forest have been seen as evidence of previous human cultivation, for example Letouzey (1968). The sweet tasting pulpy mesocarp of the fruits of I. gabonensis are reported by local people to be consumed by most of the larger mammals in the forest. Successful germination in elephant dung has also been observed. No direct evidence was recorded of other mammal dispersers but pyrenes which had small teethmarks on the remains of the mesocarp, most of which had been scraped off, were frequently found on the forest floor in the fruiting season. Unripe fruit are attacked by rodents including squirrels, which gnaw through the mesocarp and the pyrene to reach the seed. Red Forest Pigs (Potamochoeruspor cus)s plit the pyrenes open and eat the seeds. The mesocarp of the fruit starts to rot very quickly after the fruits fall and within a few weeks the soft mesocarp has almost dis-appeared. Germination then takes place with the pyrene on the surface of the soil or leaf litter, and is epigeal and phanerocotylar. The hypocotyl elongates during germination and the cotyledons are held horizontally 5-9 cm above the soil surface.
Source: Harris D.J. 1996. A Revision of the Irvingiaceae in Africa. Bulletin du Jardin botanique national de Belgique 65: 143-196.
Lower Guinea endemic. Nigeria, Cameroun, Central African Rep., Equato-rial Guinea, Gabon, Congo, Angola (Cabinda), and Zaire. Also planted in Cote d'Ivoire, Ghana and Benin.
The mesocarp is eaten as a dessert fruit, in a similar fashion to the mango (Mangifera indica). The seeds are used in cooking to provide a mucilagenous sauce which has some thick-ening and flavouring properties. Trees are planted on farms in Nigeria, Cameroun Congo and Gabon. The fruit are also gathered from wild trees. The trade in dried seeds is substantial in Nigeria, Cameroun and Gabon.
Source: Harris D.J. 1996. A Revision of the Irvingiaceae in Africa. Bulletin du Jardin botanique national de Belgique 65: 143-196.