Tree has a short thick trunk. Milky latex is present. Simple Leaves are leathery. Small, regular, bisexual Flowers may appear on the trunk. Fruit is a fleshy berry with up to 2 Seeds.
Englerophytum magalismontanum, Bequaertiodendron magalismontanum, Chrysophyllum magalismontanum, Chrysophyllum wilmsii, Sideroxylon randii, Zeyherella magalismontana.
RSA Tree No. 581.
Common names: Stem fruit, Transvaal Milkplum, Stamvrug, Milkplum.
Sapotaceae. (Stamvrug, latex-yielding family). This family include 35-75 genera and approximately 800 species. Local genera with trees include Englerophytum, Inhambanella, Mimusops, Sideroxylon and Vitellariopsis. Branches exude latex. Leaves are simple, entire and there are closely parallel secondary veins. Stipules are absent. Flowers are bisexual, usually actinomorphic (regular). There are persistent Sepals and fused Petals. The Stamens equal the number petals. Staminodes may be present outside the fertile stamens. The superior Ovary has locules containing a single ovule. One Style and 1 Stigma are present. Fruit is a berry. Seeds have a thick brown shiny testa (seed coat) with a distinct scar. There are 7 genera and 14 species in southern Africa.
Name derivation: Englerophytum – named after the first collector of the plant: Gustav Heinrich Adolf Engler (1834-1930). He was a German botanist famous for his system of plant classification. magalismontanum refers to the Magaliesberg mountains, which run from north of Pretoria (Tshwane) to just south of Pilanesberg. It was here the plant was first described. “Stamvrug” – fruit on the stem – significent. There are 2 species of Englerophytum in southern Africa. The other is E. natalensis.
Conservation Status: L C. (Least Concern). Assessment Date: 2009 (Raimondo et al.).
Tree is evergreen and up to 15m high in forests under ideal conditions. They are usually a lot shorter. In exposed, poor soil conditions they can be as short as 1m high. The Trunk is thick, usually short and can be multi-stemmed. Bark is light brown or grey, smooth, slightly scaly and flaking with age. Branches may reach down to the ground and are marked by scales of past fruit. Young stems are densely covered with dark reddish/brown hairs. On steep slopes the roots may be seen twisting around rocks. Rupturing the plant results in milky, non-poisonous, latex oozing out. The Crown is compact and rounded.
The Upper surface of these simple (has a single blade, which may have incisions that are not deep enough to divide the blade into leaflets) Leaves is glossy dark green which may be obscured above by a bloom which can give the leaves a blue-grey shiny appearance in young leaves. This bloom is easily rubbed off (photo 597). The Lower surface has silvery to red to gold brown shiny hairs and a distinctly raised midrib. They are often crowded near the ends of branchlets. Here young leaves are golden brown. The leathery mature leaves are lance to oval to obovate-elliptic shaped and usually up to 19 x 5cm. The Midrib is sunken above and the sides are bent making the young leaves V-shaped (photo 210). Lateral veins are numerous and almost parallel. They may be difficult to see behind the hair. Between these parallel veins, an additional smaller network of veins is visible with a hand lens. Leaves have brochidodromous venation (the secondary veins do not terminate at the leaf margin but are joined together in a series of prominent upward arches or marginal loops on each side of the primary vein). The rolled under Margin is entire (with a continuous margin, not in any way indented but may be hairy). The round Apex may be notched and frequently has a short hair-like tip. The rounded or narrow Base is tapers and runs slightly down the Petiole (leaf stalk). The petiole is up to 4mm wide and 2,5cm long. As the young leaf ages, the petiole bends at the junction of the blade allowing the blade to hang out horizontally. Stipules (basal appendages of the petiole) are slender and only up to 7mm long. They are caducous (an organ or part which is easily detached and shed early).
The strongly scented Flowers and may be found in large groups. Flowers are in Fascicles (condensed or close cluster of leaves or flowers) and change from cream coloured to brownish-pink and are small – about 1cm long. Flower are bisexual and actinomorphic (regular, symmetrical. Perianth, the calyx and corolla, is divisible into 3 or more identical sectors). Buds are grouped together on branches or on the trunk of old wood – not in existing leaf axils (Photo 148). The Calyx has 5 Sepals which are in a single whorl and are more or less free. They overlap and are basally connate (united or joined). The Corolla has 5 overlapping Petals which are whitish or deep red-brown. The Stamens are epipetalous (attached to the petals). Here Anthers are extrorse (turned outwards). There is a single Pistil (a unit of the Gynoecium, the female element of the flower, composed of the Ovary, Style and Stigma). The superior Ovary has a single short style. The distinct Pedicels (flower stalks), are covered in rusty coloured hairs. (Jul-Dec).
The ellipsoidal, leathery skinned, fleshy Fruit is a Berry (pulpy, indehiscent fruit like a grape or tomato) up to 2,5 x 2cm. It is usually located on old wood and on knobbly spur branchlets. The fruit is distinctively red when ripe and contains a high level of vitamin C. A persistent Calyx is visible. The fruit has a thin, leathery outer layer and may be sharply tipped with the remains of a persistent Style. The fruit has a distinct odour – pleasant / unpleasant – opinions differ. Each fruit produces 1, sometimes 2 large ellipsoid Seeds – each about 2,5cm long. They are whitish or pale brown, with a narrow scar up to 2mm wide on the side. The Testa (seed coat) is smooth and endosperm (the starch and oil-containing tissue of many seeds; often referred to as the albumen) is absent. (Dec-Feb).
Distribution & Ecology
These Trees are usually associated with quartzite and granite rocks on rocky outcrops. They are drought, cold and, to a certain extent, fire resistant. This plant is common in Gauteng: Pretoria, Johannesburg e.g. Northcliff Eco Park where it is the dominant tree, and Melville koppies. It also occurs in Magaliesberg and in the northern part of KwaZulu-Natal, Mpumalanga, North West and Limpopo. Trees occur at altitudes between 550 and 1 900m. They also occur in Zimbabwe, Swaziland, Mozambique, Malawi and Zambia. Specimens are visible in the hills close to the tower at Marakele National Park. The tree is hardy and relatively fast growing. The larva of the Butterfly “Boisduval’s False Acraea” (Pseudacraea boisduvali) feeds on the leaves. Monkeys and baboons feed on the Fruit and the Roots provide food for bushpigs.
The tasty Fruit needs to be picked early – before the arrival of many different small animals. The Fruits are used to make jelly, syrup and alcoholic beverages like brandy. The plant can be Propagated by cuttings or seeds. Fresh Seeds should be used for growing this plant. Planted seeds take some time to develop.
Boon, R. 2010. Pooley’s Trees of eastern South Africa. Flora and Fauna Publications Trust, Durban.
Coates Palgrave, M. 2002. Keith Coates Palgrave Trees of Southern Africa, edn 3. Struik, Cape Town.
Lawrence, G. H. M, 1951. Taxonomy of Vascular Plants, The Macmillan Company, New York. Tenth Printing 1965.
Palmer, E. & Pitman, N. 1972. Trees of southern Africa, Balkema, Amsterdam, Cape Town.
Schmidt, S. Lotter, M. & McCleland, W. 2002. Trees and Shrubs of Mpumalanga and the Kruger National Park.
van Wyk, B. & van Wyk, P. 1997 Field guide to Trees of Southern Africa, Struik, Cape Town.