Hexalobus monopetalus (A.Rich) Engl.& Diels
Common names: shakama plum, baboon’s breakfast, wild custard apple (Eng.), bastersuikerappel, shakamapruim (Afr.), muhuhuma (Tshivenda), moheteka, mowedika (Northern Sotho)
During the fruiting season, the magnificent Shakama plum is one of the trees that produces delicacies that are relished by herdboys and wood collectors.
The 2–9 m tall Hexalobus monopetalus is a deciduous shrub or small, crooked tree with a scattered spreading canopy. It has a slender, twisted stem with low branches that range in colour from brown to black and are covered in light brown hair. The leaves of this wonderful tree have a petiole up to 4 mm long, and the leaf blades are 36-175 x 12-65 mm, leathery, glossy green, obovate, with visible venation on both surfaces. The tops of the leaves have long, obscure lateral veins and brown hairs that are evident along the midrib.
The flowers are found either singly or in groups of 2 or 3, on very short stalks (subsessile), in the axils of the leaves, on leafless twigs or sometimes from the trunk, and emerge when the plant is without leaves. The flowers are made up of 3 sepals and 6 petals. The sepals are brown on the outside, 4-7 mm long and enclose the petals until the flower opens. The petals are pale yellow, greenish or cream, fused at the base forming a short tube, up to 4 mm long, with 6 narrowly lance-shaped lobes 12-22 mm long, that appear crumpled or wrinkled when the flower is open. These 6 fused petal lobes are a key characteristic which has given this tree its scientific name. Hexalobus monopetalus blooms in spring (August and September) and produces edible fruits that ripen in late summer, from January to April. These fruits are 15-50 x 10-25 mm, cylindrical to obovoid, sometimes constricted between the seeds, scarlet when ripe. They can be harvested before they are fully developed on the tree, although they are typically picked at that time to allow for further ripening. The pulp of the ripened fruit is bright yellow and has a sweet, pleasant acidic flavour.
Hexalobus monopetalus is not threatened and is thus assessed as Least Concern (LC) in the Red List of South African Plants.
Distribution and habitat
Hexalobus monopetalus may be found all throughout northern South Africa and is particularly widespread in the province of Limpopo. It has even been spotted as far south as Sekhukhuneland in Mpumalanga. This species’ distribution spans all of Africa, from the tropical regions to the westernmost parts of the continent. It can be found growing in sandy bushveld, woodland, savanna, rocky outcrops, riverine thicket and on hillsides , often among rocks or stones, from sea level to 1 600 m.
Derivation of name and historical aspects
Hexalobus monopetalus has one of the widest distributions in the African members of the Annonaceae family, reaching all the way from West Africa to East Africa and South Africa. The five species of trees and shrubs that make up the genus Hexalobus can be found in a wide range of habitats in tropical Africa, from primary rain forest to savanna and woodland. This species was first described as Uvaria monopetala by the French botanist Richard in 1831. A year later, de Candolle created the genus Hexalobus, separating it from the genus Uvaria by the basally fused corolla lobes. He identified two species from this genus, H. senegalensis and H. madagascariensis, but he classified the earlier name Uvaria monopetala as a synonym of H. senegalensis, making this latter name redundant and hence invalid.
The name Hexalobus is derived from the Greek hexa, meaning ‘six’ and lobos meaning ‘lobes’, referring to the 6 basally fused petal lobes. The species name monopetalus means ‘having one petal’, or ‘having a corolla made up of petals that are fused’ which also refers to the basally fused corolla lobes. This feature was chosen for the names because it is unique in the Annonaceae.
Hexalobus monopetalus reproduces mainly by seed. These seeds are thought to be mostly bird-dispersed. The fruit of this tree is usually infested with insects and can be larval plant food for several swordtail butterflies.
In the many countries it occurs in, Hexalobus monopetalus is used to treat a variety of illnesses, including fungal skin infections, stomach ulcers, sexually transmitted infections, inflammatory diseases, and to heal wounds. A decoction made from the bark of Ficus glumosa together with the root of Hexalobus is used to treat diabetes. The entire plant can be used to cure chest aches, diarrhoea, and colds.
A fibre produced by the bark is frequently used for cordage and the wood is highly valued for making hut poles and to make chair legs, tool handles, bows, spoons, gunstocks and carvings. The wood is also recommended as a good source of firewood for cooking as well as for heating. The fruit produced by this tree can be eaten raw or cooked and used to make jam.
Growing Hexalobus monopetalus
Plants in the family Annonaceae are best grown from seed. The seeds inside the fruit need to be exposed by cutting away the tough outer covering, and then they need to be planted in a medium that allows enough drainage. About 80% of seeds will germinate between 1-3 months after planting.
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Sithi Ngamlana & Mpho Mathalauga
Pretoria National Botanical Garden
Acknowledgements: The authors thank Ntsakisi Masia, Chris Wahlberg and Malcolm Douglas for the photographs.
Plant Type: Shrub, Tree
SA Distribution: Limpopo, Mpumalanga
Soil type: Sandy, Loam
Flowering season: Spring
Flower colour: Brown, Green, Yellow
Aspect: Full Sun
Gardening skill: Average