General Info – summary.

This spineless, deep-rooted, stocky and whitish Tree may reach 10m high or is a small shrub.  Stout branches are crooked.  Small simple entire & coriaceous Leaves are alternate and become hairless.  Star-shaped, bisexual, yellowish-green Flowers are in racemes, have 4 sepals, lack petals, have yellow stamens. Pistil with a superior 1-locular ovary rest on a gynophore.  Fruit is usually 1-seeded berry with sclereids.

Description.

Boscia albitrunca.

Previous Names: Previous Names: Boscia pechuellii, Boscia puberula Boscia transvaalensis, Capparis albitrunca. Capparis oleoides, Capparis punctate.

SA Tree No. 122.

Common names:  (Afr) Grootwitgat, Grootwitgatboom, Grootwitgat, Groot-witgat, Grootwitgatboom, Jentelmanstam, Kaboom, Koffie, Koffieboom, Matoppie, Noenie, Noenieboom, Witbasboom, Witgat, Witgatboom, Witstam, Witstamboom, Witteboom.  (Eng) Caper Bush, Coffee Tree, Emigrant’s Tree, Shepherd Tree, Shepherd’s Tree, Tree of Life, White Stem, White-stemmed Tree.  (IsiNdebele) Umbombwe, Umhlope, Umtopi.  (isiXhosa) Umgqomogqomo, Umpunzito.  (isiZulu) Inyokiziphinda, Isikhwelampisi, Isinama, Umfithi, Umvithi.  (Northern Sotho) Mohlopi, Mohlôpi.  (Setswana), Motlhôpi, Motlopi, Motlôpi.  (siSwati) siPhiso.  (Tshivenda) Muthobi, Muvhombwe.

Family: Capparaceae. (The caper family) has about 16-33 genera and 480-700 species.  This family has trees, shrubs and some lianas (climbing plants that are woody and hang from trees) and herbs.  Members are tropical and sub-tropical.  Flowers are usually 4-merous.  The superior Ovary usually has 1 locule.  Fruit is a capsule or a berry.  Mustard Oils are present in all genera.  Local genera on this website include Boscia and Maerua.

Name derivation: Boscia – Louie Augustin Guillaume Bosc (1759-1828) was a French botanist, invertebrate zoologist and entomologist.  He also wrote the first ever-systematic examination of the mushrooms of the southern USA.  albitrunca – refers to the trunk which may be white.  The Genus Boscia has 37 species.  There are 9 species in southern Africa.

Conservation: National Status: L.C. (Least Concern).  Assessed: 2005 (W. Foden and L. Potter).  Due to its high regard in many local traditions, the tree is somewhat protected.

Tree

This tree has the deepest roots of any plant in the world.  They reached a measured depth of 68m in the Kalahari in Botswana.  A close runner-up may be Vachellia erioloba (Acacia erioloba) with a root depth of 60m.  This often single-stemmed Tree may reach 10m in height but is usually smaller with a much-branched crown (photo 86).  However, it can also have a stout branched trunk or even become multi-stemmed or a low mat over rocks.  The Stem (main axis of the plant, the leaf and flower bearing as distinguished from the root-bearing axis – photo 89) is usually twisted and usually whitish with strips of darkly coloured Bark.  The trunk may also be black or orange brown.  The stem is folded and seamed and may be pitted – (photo 89).  The light, Trunk may be visible from a distance and makes identification easier.  Light coloured Lenticels (a usually raised corky oval or elongated area on the plant that allows the uncontrolled interchange of gases with the environment) are present on branches (photo 921 under Leaves).  The Crown is compact and rounded in open spaces.  The stout Branches are crooked and spineless.

Leaves

The stiff, simple and coriaceous (leathery) Leaves develop in groups of 2-4 (photo 921) on slight spur branches.  They are alternate on young branches or fascicled (condensed cluster of leaves) and are evergreen, but some leaves are lost when the flowers appear.  Leaves are usually slightly oblanceolate (leaf broader at the apical third than at the middle and tapering towards the base e.g., photo 921) or elliptic (photo 924).  The Apex is rounded or abruptly tapering, (photo 924) and often bristle-tipped, whereas the Base tapers.  The Margin is entire (with a continuous margin, not in any way indented).  Leaves may reach 8 x 2,5cm but are usually smaller.  Mature leaves are hairless and have a distinct Midrib (photo 924).  Other veins are obscure unless the translucent leaf is viewed against a strong light (photo 923).  This is a worthwhile exercise as the veins become distinctive.  I found the early mornings and late afternoons are the best times to take these photos against the sun.  These side veins loop before reaching the margin.  The upper surface of the blade may be shiny and slightly darker than the lower surface (photo 924).  On this photo, the thin Petiole (leaf stalk) is short (up to 4mm long).

Flowers

The star-shaped, bisexual and strongly sweet-scented Flowers mainly develop in axillary clusters or on short spur branches and often-on old wood (photo 81).  Pedicels (stalks of single flowers) are visible (photo 57).  The 4 fleshy, yellowish green, hairy Sepals (photo 242) are scarcely fused at base.  Sepals are lanceolate and may touch but do not really overlap.  Petals are absent (photo 242).  The central group of numerous short yellow, hairless Stamens all have almost free Filaments that have a small fusion joining them just at their base.  The Anthers have 2 Theca (pollen sacs) which open by longitudinal slits.  There is a single Pistil (a unit of the gynoecium – composed of the stigma, style and ovary) rests on a short Gynophore (a stalk present in some flowers that supports and may elevate the gynoecium) which is up to 8 mm long (photo 242).  The ovoid, 1-locular superior Ovary has a single short Style with a capitate (formed like a head) Stigma (photo 246 under Fruit).  Flowers often occur in profusion after spring rains.  Trees do not flower every year.  (Jul-Nov but usually Sep-Oct).  They may appear outside this time e.g., after rain).

Fruit

When ripe, the hairless, yellowish or light brown Fruit is up to 1,2cm wide – about the size of a small cherry.  The initially green fruit (photo 246) ripens to light brown (photo 759).  In Namibia, it may become mauve.  It is an almost spherical Berry (pulpy, indehiscent fruit like a grape or tomato) up to 1,5cm wide.  Each berry has clusters of stone cells (plant cells with highly thickened, lignified cellular walls) in the brittle exocarp (skin; the outer layer of the pericarp of a fruit).  The middle layer or mesocarp is the juicy part and has a whitish flesh.  The endocarp (the inner layer of the pericarp or fruit wall) is large.  Berries lack ribs.  The single Seeds usually lack endosperm (the starch and oil-containing tissue of many seeds – often referred to as the albumen).  (Nov-Mar).

Distribution & Ecology

This is a protected tree in South Africa.  Apart from the Eastern and south Western Cape, this is one of the more widespread of trees of southern Africa and is most obviously located in the dry Northern Cape e.g., the broken country near Springbok, Free State, and North West.  It also occurs in KwaZulu-Natal, Free State, Gauteng, Limpopo and Mpumalanga.  It is absent from the Eastern Cape.  Beyond South Africa, the plant grows in Swaziland, southern Mozambique, Botswana, Namibia, Zimbabwe, Zambia, and into tropical Africa.  Because it is able to survive in very dry places, it is common on the red sands of the Kalahari Desert.  Trees occur in hot dry areas as well as in the bushveld, open woodland and are often associated with termite mounds.  Trees grow bigger when more water is available.   Leaves have high vitamin A and C levels and a high (14%) protein content.  All herbivores consume the leaves and are considered by some to be as good as lucerne”.  Herbivorous animals account for the often-visible grazing line at the base of the tree crown.  They shoot again after being damaged.  Butterflies, whose larvae consume the Leaves, include the Browned White (Beleonis aurota) which is common in Africa and India, the African Common White or African Caper (Belenois creona) and the Zebra White (Pinacopteryx eripha eripha).  Elephants eat the Bark.  Both birds and animals – including kudu, giraffe and gemsbok, consume the FruitFlowers attract masses of insects (agents of pollination) and are also eaten by antelope.  This tree aids animal survival, especially in dry areas.

Ethnobotany

In very dry areas, this may be the only Tree that provides both shade and valuable grazing for stock – especially in hot dry areas.  Local branches may be cut to feed livestock. These cut branches soon develop new shoots.  Old trees may become hollow and store water – this is useful in times of need.  Local people also eat the acrid Fruit.  Roots are useable for making a “reasonable” coffee or beer.  Ground roots produce a white meal which is used for porridge.  A syrup made from boiled roots is reputed to be good.  Propagation is by seeds or cuttings.   However, seed development is unpredictable.  Healers use parts of the Tree, which is also has believed to have magical values.  Milk from cows that eat the leaves may be tainted.  Wood is heavy, tough and is suitable for making household implements including tables and chairs.

References

Boon, R. 2010. Pooley’s Trees of eastern South Africa. Flora and Fauna Publications Trust, Durban.

Burrows, J.E., Burrows, S.M., Lotter, M.C. & Schmidt, E. 2018. Trees and Shrubs Mozambique.  Publishing Print Matters (Pty) Ltd.  Noordhoek, Cape Town.

Coates Palgrave, M. 2002. Keith Coates Palgrave Trees of Southern Africa, edn 3. Struik, Cape Town.

Foden, W. & Potter, L. 2005. Boscia albitrunca (Burch.) Gilg & Gilg-Ben. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2022/09/29.

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. Jacana, Johannesburg.

van Wyk, B. & van Wyk, P. 1997 Field guide to Trees of Southern Africa. Struik, Cape Town.

Woodhall, S. 2020. Field Guide to Butterflies of South Africa, edn 2. Donnelley, RR, China.

 

http://posa.sanbi.org/flora/browse.php?src=SP

https://www.revolvy.com/main/index.php?s=Louis%20Augustin%20Guillaume%20Bosc

https://en.wikipedia.org/wiki/Boscia_albitrunca

http://pza.sanbi.org/boscia-albitrunca

https://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=124480