Tree 10-20m high has strong spines. Compound Leaves with 2 Leaflets. The small, greenish-yellow, bisexual and regular Flowers in axillary umbels. Fruit is an oval shaped drupe.
RSA Tree No. 251.
Common names: Green Thorn, Groendoring, Y-thorned Torchwood, Torch Wood, Torch fruit tree, Fakkelsaadboom.
Family: Zygophyllaceae. This is a family of flowering plants with about 22+ genera and 280+ species. There are about 8 genera and 47 species in southern Africa. These includes the genus Balanites. The simple Leaves are usually opposite or nearly so. Flowers have oil or nectar glands to encourage pollination by bees. The Ovary is superior and the style and stigma are usually simple. The Fruit is a capsule or berry.
Name derivation: Balanites from Greek for acorn-shaped – referring to the fruit. maughamii – named after R C F Maugham who first collected the plant in southern Mozambique. There are 4 species of the genus Balanites in southern Africa.
Conservation Status: Declining. 2009 (Raimondo et al.). This is mainly due to habitat loss and bark harvesting for traditional medicine. The tree also has a poor wound recovery.
As the Tree ages the trunk usually becomes distinctive fluted (grooved, funnelled, channelled), grooved and buttressed. The Trunk is up to 30cm+ wide and branches just under 2m above the ground. The spreading crown reaching up to 20m in height. The Bark is smooth sometimes scarred by porcupines and the young twigs are often form zigzag patterns. Some branches are fruit bearing with few or no Spines while others, non-fruit bearers, have strong, sharp spines that are up to 4cm long. These spines are often unevenly forked – one being longer than the other. Young branches are often covered with grey-green hairs, which remain for some time.
This deciduous tree has compound Leaves containing 2 alternatively arranged leaflets. The 2 Leaflets are grey or olive-green and up to 6 x 5,7cm. The Apex is pointed to rounded or more or less egg-shaped. The Base is asymmetric and broadly tapering. The Blade is entire (with a continuous margin, not in any way indented) and may be wavy. It has an off-centre Midrib. Leaflets are initially hairy but the upper surface becomes smoother with age. The hairy Petiole (leaf stalk) is up to 3cm long. Petiolules (leaflet stalks) are up to 1,3cm long.
The scented, bisexual Flowers are small – up to 2cm wide and actinomorphic (regular, symmetrical. Perianth, the calyx and corolla, is divisible into 2 or more identical sectors). They are located in axillary umbels-like (inflorescence in which flower stalks arise from a common point) cymes (a broad, more or less flat-topped, determinate flower cluster, with central flowers opening first). The Calyx has 5 free, persistent Sepals – the outer surface of which is villous (provided with long and soft, not matted, hairs; shaggy). The Corolla has 5 greenish-yellow Petals which are slightly fleshy and imbricate (having regularly arranged, overlapping edges, as roof tiles). A thick Disc (a more or less fleshy or elevated development of the receptacle) is present. The 10 Stamens have distinctive protruding Filaments that are inserted at the base of the disc. The filaments are free and the Anthers have 2 pollen sacs which open by longitudinal slits. There is a single Pistil (a unit of the Gynoecium, the female element of the flower, composed of the Ovary, Style and Stigma) containing a superior, 5 chambered, globose (spherical or nearly so) Ovary. This 5-locular ovary is hairy and partly imbedded in the disc. Each locule contains 1 ovule. The Style is short and the Stigma is simple. (Jul-Nov).
The Fruit is an oval shaped Drupe (a fleshy, 1-seeded indehiscent fruit with the seed enclosed in a stony endocarp; stone fruit e.g. peach). This drupe usually has 5 grooves and is up to 6 x 3cm. Each fruit has a shell, which is brownish yellow. A thin fleshy layer surrounds this. The drupe is 1-seeded by abortion. The Seed has 2 oily Cotyledons (seed leaves; primary leaves in the embryo) and lack endosperm (the starch and oil-containing tissue of many seeds; often referred to as the albumen). (May-Jul).
Distribution & Ecology
These Trees are located dry forest, open woodland, coastal forests and around pans. They are found in Northern KwaZulu-Natal e.g. Mkuze Game Park, Mpumalanga e.g. Skukuza in KNP, Limpopo and Northwards through Mozambique (mainly central and south) and include Zimbabwe and Tanzania. Elephants browse the Branch tips. Many mammals including baboons, monkeys, warthogs, bushpigs and antelope consume the Fruit. (Sep-Mar).
Planted trees may take up to 4 years to produce the edible Fruit. Fruits placed in water can kill snails, fish and tadpoles. The stem of the tree contains steroidal saponins (distinctive glycosides with foaming characteristics) with an antifeedant (chemical agent that causes a pest such as an insect, to stop eating). The hard, dense and durable Wood is used to make sticks, stocks for guns, wooden bowls and handles for pangas (tools or weapons). Heartwood and sapwood are indistinguishable. The tree yields good quality edible, colourless and slightly bitter, flammable Oil. Burning kernels (a softer, often edible part of a nut, seed, or fruit stone contained within its shell) are used as torches. The tree can easily be grown from seed after the fleshy part has been removed. Root extracts are used as an enema. This tree has been cultivated in Egypt for over 4 000 years.
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