Tree is up to 16m high. The simple, entire Leaves are estipulate and shine in the sun. The whitish, actinomorphic Flowers lack petals and are in spikes. Fruit is a samara with 2-winged Seeds.
RSA Tree No. 551.
Common names: Silver Cluster-leaf, Vaalboom, Assegai wood, Silver Terminalia.
Family: Combretaceae (Bushwlillow family). In this family, there are about 16 genera, which contain about 530 species. In the RSA, there are 5 genera and 41 species. The RSA genera with trees are Combretum, Lumnitzera, Pteleopsis and Terminalia. The simple and usually entire Leaves lack stipules. Flowers are usually bisexual. There are usually twice the number of stamens as sepals or petals. The inferior Ovary has 1 locule and usually only 1 of the ovules develops into a seed. Fruit is usually indehiscent and may be winged or ridged.
Name derivation: Terminalia – end: referring to the fact that leaves are gathered at the ends of shoots. sericea – clothed in silky hair – referring to the silky coloured leaves which are especially visible in sunlight. The genus Terminalia has 7 species in southern Africa.
Conservation Status: L C. (Least Concern). 2009 (Raimondo et al.).
This Tree has a roundish spreading to flat-topped crown that is usually up to 16m high. It is single stemmed, and erect. The Trunk diameter is up to 46cm. Bark is dark and deeply, longitudinally fissured with ridges joining and splitting. The bark tends to peel. On Young branches the peeling and flaking reveals a light brown underbark. The twigs (1-year-old current branch segments) are red-brown or purplish black and covered with silky hairs. Branches tend to be layered. The ends of branches tend to droop. There are no scales or stalked glands present. Woody Galls (abnormal outgrowths of tissue caused by fungi, bacteria, insects or mites), up to 3cm in diameter, may appear on the branches.
This deciduous tree has simple Leaves that are clustered or spiralled and located towards the ends of slender branchlets. The slightly hairy leaves are grey-green or silvery and paler below. When young, the leaves are covered with silky, silver-grey hairs. The silky hairs give the leaves their characteristic sheen. Some leaves are hairless and leaves become less hairy as they age. Leaves are slender, oblong to obovate (the reverse of ovate) or lanceolate (lance shaped) and up to 12 x 4,5cm. The leaves are wider above the middle of the leaf. The Apex is tapering or bluntly pointed or sometimes rounded and ends in a short tip. The Base tapers narrowly. There are up to 16 pairs of Lateral Veins, which are obscure but more visible above. The Margins are entire (with a continuous margin, not in any way indented but may be hairy). The Petiole (leaf stalk) is short – up to 1cm.
The very small, pale yellow to creamy white Flowers are and about 4mm wide. They are inconspicuous and borne at ends of branchlets. Flowers are actinomorphic (regular, symmetrical. Perianth, the calyx and corolla, are divisible into 2 or more identical sectors). Some bisexual flowers are located at the base of the Spike (simple indeterminate inflorescence with sessile flowers on a single unbranched stalk) which is up to 7cm long. Some flowers may be male only and these occur towards the end of the same spike. The Male flowers have stalks which resemble pedicels (flower stalks) but correspond to the lower receptacle with abortion of the ovary. Flowers lack Petals and the Calyx forms a tube above the ovary. The mouth of the tube is hairy. The calyx is attached to the edges of the shallowly cup-shaped Receptacle (that expanded tip of the flower stalk from which the floral parts develop). The 10 Stamens are exserted (sticking out; projecting beyond) the sepals. The Disc (a more or less fleshy or elevated development of the receptacle) is intrastaminal (found between the stamens). In the Bisexual flowers 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 Ovary is completely inferior (one which is below the calyx). Flowers have an unpleasant smell, which might suggest that pollination is by, or includes, flies. (Sep-Jan).
The oval, flattish, round-tipped Fruit is swollen in the centre. It is a pseudocarp or samara (an indehiscent winged fruit), which contains a single seed. Unlike many Combretum species, the fruit has 2 not 4 Wings that surrounds the seeds. These wings are thin. Fruit is up to 4 x 2,5+cm and is attached by a short stalk that is up to 5mm long. Fruit is initially pink to red but darken with age becoming reddish brown. The fruit, together with the leaves, gives the tree an attractive silver and pink colour. Short hairs may be present. The fruit may remain on the tree for an extended period of up to a year. They are finally wind dispersed. (Feb-May).
Distribution & Ecology
Sandy bushveld is the ideal environment for this tree. It also is found on the slopes of vleis (a vlei is a shallow, small, seasonal lake or pond or marshy wetland). These trees can be the dominant or co-dominant tree e.g. with Brachystegia, Colophospermum mopane, Combretum or Acacia forest. Location: KwaZulu-Natal, Northern Cape but not in the central Kalahari. They also occur in Mpumalanga e.g. Kruger National Park, Gauteng, Limpopo, North West e.g. Hartebeestpoort dam area, Swaziland, Botswana, Namibia, southern Mozambique, Zimbabwe, Angola, DRC and Tanzania. A group of trees appears as a silvery wood. Antelope browse fallen leaves while both elephant and giraffe consume the attached leaves. The leaf nutritional value is reported to be low. Leaves are the food plant for larvae of the guineafowl butterfly (Hamanumida daedalus). This butterfly mainly feeds on Combretum species but also feeds on some Terminalia species. The larvae of the moth Laeliopsis punctuligera also feeds on this plant. Fruits may become parasitized, twisted and hairy (photo 107).
Cattle browse dry Leaves. Tswana people use the silvery leaf hairs to glaze their pottery. Wood is yellow, close-grained, hard, strong and elastic as well as being termite and borer proof when properly seasoned. It is oily and makes good fence posts and furniture. Wood is used for construction of hoe-handles, bows and huts and makes a good fuel – including charcoal. The Bark is used for tanning, providing a yellow colour, and is striped and used for making rope. Trees yield an edible Gum. It is a difficult tree to grow especially in heavy soil. It can withstand some frost and is drought resistant. Germination rate is low but, once established, the tree grows relatively quickly in sunny places. It can form dense thickets when cut or burnt, and may become weedy.
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