Medium sized Tree. Bark has lenticels in horizontal groups. Imparipinnate Leaves are hairless. The dioecious small Flowers are whitish. Fruit is an indehiscent 1-seeded drupe.
RSA Tree No. 361.
Common names: Wild Plum, Sour Plum, Essenhout.
Family: Anacardiaceae (Mango family, which has about 83 genera and 850+ species – including Cashew). Resin canals are present. All young parts are covered with woolly stellate hairs. Leaves all lack stipules. They are deciduous or evergreen and usually alternate. Leaves are simple, trifoliate or digitally compound and imparipinnate. When present, leaflets are usually opposite. Crushed leaves may smell of turpentine. Trees are monoecious or dioecious with occasional bisexual Flowers. Flowers are small, usually regular and unisexual. The Calyx has 4-7 sepals and there are 4-7 Petals. The number of stamens is the same as, or twice the number of petals and the anthers are versatile. The superior Ovary has up to 4 locules, each with a single ovule. The 1-5 styles are free or connate and separated at the base. Fruit is usually an indehiscent fleshy drupe with a single seed. The southern Africa genera include Harpephyllum, Lannea, Loxostylis, Ozoroa, Sclerocarya and Searsia.
Name derivation: Harpephyllum refers to the sickle shape of the leaflets. caffrum – from the Eastern Cape.
Conservation Status: L C. (Least Concern). 2009 (Raimondo et al.).
This Tree resembles Ekebergia capensis (in the family Meliaceae) and is usually up to 10m high but may reach 15m. Damaged parts exude watery sap. In Ekebergia capensis there is no watery sap, leaflets are not sickle-shaped and there are no red leaves. In Harpephyllum caffrum the stem is usually straight and smoothish and the Base may be buttressed. The Branchlets have thickened endings and branches tend to curve upwards. The Bark is brown or silver white with raised Lenticels (usually raised corky oval or elongated areas on the plant that allow the interchange of gases with the environment) which occur in horizontal running groups. It may also contain visible segments and becomes grey-brown with age. Roots may appear on the forest floor.
The spirally arranged Leaves on this evergreen tree tend to be crowded towards the ends of branches. They may remain for up to 2 years and may turn bright red before they fall. This is a distinctive characteristic. Each leaf may be up to 30cm long. Collectively the leaves form a thick apical crown. Individual leaves are imparipinnate (pinnately compound leaf ending in a single leaflet). The hairless leaves are smooth and leathery. The Rachis (main axis bearing leaflets) may be slightly winged. Apart from the terminal leaflet, the remaining Leaflets may be slightly sickle-shaped (this is not so in Ekebergia capensis). In H. caffrum there are 4-8 pairs of leaflets that are opposite or nearly so. In addition, there is a single terminal leaflet. Most leaflets are dark shiny green above and lighter and dull below. Each leaflet may reach 10 x 2,5cm and there are 6-8 pairs of lateral veins that are more clearly seen above. The Apex is narrowly tapering. The Base is asymmetric (not equal to the opposite side as in the bases of some leaves). The terminal leaflet may be lanceolate (lance shaped). The Margins may be wavy and are entire (with a continuous margin, not in any way indented). The Midrib lies to one side of the leaflet and is slightly raised on both surfaces and ridged on both sides. The Petiole (leaf stalk) is grooved or ridged on the upper side and is up to 10cm long. The Petiolules (stalks of leaflet) are very short or absent. Stipules (basal appendage of the petiole) are absent. The there are no red leaves in Ekebergia capensis whose leaves tend to droop and this drooping is less obvious in Harpephyllum caffrum.
On this Dioecious (having male and female parts on separate trees) tree, the small, whitish Flowers occur in axillary Panicles (indeterminate, branched inflorescence with stalked flowers). Flowers are. There are 4-5 sepals and petals. Male Flowers have 7-10 Stamens present. Filaments are free. The Anthers are 2-thecous (with 2 pollen sacs) which dehisce longitudinally. Here the Ovary is vestigial (imperfectly developed, non-functional relic from the past). The Female Flowers have a Disc (a more or less fleshy or elevated development of the receptacle) which is saucer-shaped with a scalloped rim. There are conspicuous Staminodes (sterile stamens) present. There is a single Pistil (a unit of the Gynoecium, the female element of the flower, composed of the Ovary, Style and Stigma) and the superior Ovary has 1 pendulous ovule. Locules have thick walls. There are 4 or 5 separate Styles and the Stigmas are truncate (appearing as if cut of at the end). (Nov-Feb).
The thinly fleshy Fruit is an indehiscent Drupe (a fleshy, 1-seeded indehiscent fruit with the seed enclosed in a stony endocarp; stone fruit e.g. peach). They may be produced in large numbers. Each drupe resembles a plumb and is up to 2,5 x 1,3cm. Ripe fruit becomes red. Fallen fruit often covers the ground below the trees. The flattened Seeds are reniform (kidney-shaped). (Mar-Aug).
Distribution & Ecology
This Tree is a forest dweller – especially in coastal and riverine forests. It is found from the Eastern Cape, KwaZulu-Natal, Northern Province, Mpumalanga and Limpopo. It also occurs in Swaziland, Mozambique and Zimbabwe. Monkeys, baboons, bats and bushpigs consume the Fruit. Birds, including the Trumpeter Hornbill, Knysna turaco (Knysna Loerie), Mousebirds, Barbets and African Green Pigeons eat the Flesh. The Cape Parrots consume the kernel after successfully breaking through the stony endocarp). Larvae of the common Hairtail butterfly (Anthene definite) and the Eggar moth (Lasiocampa kollikerii) feed on the Leaves. The carrot Fern Asplenium rutifolium and many epiphytic Orchids may occur on this tree.
The rather sour Fruit is edible. It makes a good jelly and a rose wine. The Wood is pale red, fairly dense and strong but not very durable. Uses include furniture, beams and fuel. The tree Grows easily from seed or truncheons in areas with little frost. Note: separate male and female trees are necessary for fruit development. This is a good shade tree. Good cultivated specimens are in the grounds of the House of Assembly in Cape Town.
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Lawrence, G. H. M, 1951. Taxonomy of Vascular Plants, The Macmillan Company, New York. Tenth Printing 1965.
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