General Info – summary

This medium sized, slow growing and deciduous Tree has drooping branches.  Variable, simple and wavy Leaves have entire margins and lack stipules.  Small, regular, bisexual, 4-merous and sweetly scented Flowers are in spikes.  They have 4 small sepals & 8 exserted stamens in 2 equal rows & are inserted in the upper receptacle.  The ovary is completely inferior.  The indehiscent 4-winged Fruit contains a single seed.

Description

Combretum collinum subsp. suluense

Previous Names: Combretum binderanum, Combretum fischeri, Combretum griseiflorum, Combretum junodii, Combretum makindense, Combretum mechowianum, Combretum suluense.

SA Tree No. 541.2.

Common names: (Afr) Boswilg, Treurboswilg.  (Eng) Bush-willow, Weeping Bushwillow.  (isiZulu) Imbondvo-lemhlophe, Umbondwe omhlophe.  (SiSswati) Imbondvo—lemhlophe.   (Tshivenda) Muvuvha.

Family: Combretaceae (Bushwlillow family).  In this family, there are about 16 genera, which contain about 530 species.  In South Africa, there are 5 genera and 41 species.  Genera with Trees on this website include 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:  Combretum – climbing plant.  collinum – Collatina was the Roman goddess of the hills and downs.  Her name came from Latin: collis, hill, high ground, or mountain.

Conservation: National Status: L C. (Least Concern).  Assessment: Raimondo et al. (2009).

Tree

The Tree is either single stemmed – up to 15m high or multi-stemmed.   The Trunk may be twisted.  The Crown can be rounded or flat.  Branches tend to droop and may reach the ground.  Soft, short and silvery hairs usually cover the Branchlets (usually applied to branches of the current or preceding year).  The roughish Bark is grey-brown and white markings may be present (photos below).

Leaves

This deciduous plant has variably shaped Leaves that are up to 12 x 4,5+cm.  Leaves on cultivated trees may be bigger.  Leaves are alternate (photo 690) to opposite (photo 694) or sub-opposite.   All are simple (have a single blade which may have incisions that are not deep enough to divide the leaf into leaflets).  Young leaves are wavy (photo 694), have a variable shape, and are roughly elliptic obovate, ovate or lanceolate.  They are initially hairy but most hairs are lost as the leaf matures.  Leaves are usually broadest in the central part.  They are often drooping and have scales, which can make them yellowish (photo 694).   The upper shiny leaf surface is dark green (photo 690).  The lower duller green to silvery surface is lighter.  The Midrib is visible on both sides but prominently protrudes below.  Here the one main vein – the midrib has side veins that loop together prior to reaching the margin.   There are 7-10 pairs of lateral Veins present.  Net veining is indistinct (photo 606).  The Margin is entire (with a continuous margin, not in any way indented).  The Midrib is visible on both sides but prominently protrudes below.  The Apex is broadly tapering to rounded and may end in a sharp point (photo 606).  The Base is rounded to broadly tapering or lobed.  The Petiole (leaf stalk) may be hairy and is up to 3cm long.  Stipules (basal appendages of the petiole) are absent.  Prior to falling in autumn, the leaves change to yellowish colour.  Hair-tuft Domatia (tiny chambers produced by plants that house arthropods may be visible.  To the naked eye the domatia appear as small bumps) may be visible close to leaf axils on the lower side of the leaf.

Flowers

The white to yellow or greenish, sweetly scented and 4-merous (having a specific number of parts – here 4) Flowers are small – up to 5mm in diameter.  These flowers develop in axillary (growing between stem and leaf) Spikes (simple indeterminate inflorescence with sessile flowers on a single unbranched axis opening in succession towards the apex – photo 692).   The spikes are usually up to 10cm long and often seen with old leaves (photo 692).  Flowers are bisexual and actinomorphic (Regular, symmetrical.  Flowers are vertically divisible into similar halves by more than 1 plane passing through the axis).  In individual flowers, the Calyx has 4 green Sepals (photo 691) which extend above the ovary.  Like most members of the genus Combretum there are 8 Stamens (10 in Combretum bracteosum) that are in 2 whorls which protrude beyond the rest of the flower (photo 691).  There is a single Pistil (a unit of the Gynoecium, the female element of the flower, composed of the Ovary, Style and Stigma).  Here the completely inferior Ovary can be mistaken for the absent Pedicle (stalk of a single flower – photo 691).  The single, free Style extends even before the Stamens emerge.  (Jul-Oct).

Fruit

The 4-winged indehiscent Fruit is rusty-red when young, becoming brown and plum-coloured or greyish. It has a red scale induced metallic sheen when mature.  The fruit is densely hairy, variable in outline, and almost round or slightly elongated (photo 695).  The fruit is up to 5,5 x 4,5cm.  Old fruit may remain on the tree for a long time, and once detached the Seeds remain viable for an extended time.  (Nov-Aug).

Distribution & Ecology

This slow growing plant is common in dry shrubland and is not endemic in South Africa.  The Trees grow in mixed bushveld (is a sub-tropical woodland ecoregion of southern Africa).  Trees also occur in open woodland at low to medium altitudes (up 1 400m).  In South Africa they are located in Northern KwaZulu-Natal, Mpumalanga and Limpopo.  Beyond South Africa, they occur in Swaziland, Northern Botswana, Namibia, central and northern Mozambique, Zimbabwe and northwards to include Senegal and Somalia.  Game, including elephant consume both Branches and Leaves, and kudu and steenbok consume the leaves.  These plants are reasonably tolerant of grass fires.

Ethnobotany

The slow growing tree responds well to Coppicing (when young tree stems are repeatedly cut/burned down to near ground level and this causes regrowth from the stump or roots).  Lopping (a process of trimming branches to modify the shape of a tree) and Pollarding (process for removal of upper branches to enhance leaf growth) are both well tolerated and used by farmers.  The Wood is reasonably hard, but not very durable and is sensitive to borer attack.  It is difficult to distinguish between the whitish-brown sapwood from the light brown heartwood.  The wood is used for building wagons, canoes, tool handles, hut frames, firewood and good charcoal.  Cattle browse the Leaves.  The Bark yields edible gum.  Research at Makerere University in Kampala, Uganda has found that an extract from shoot bark of this tree can produce larvicidal activity against the yellow fever mosquito (Aedes aegypti).  This mosquito can also spread dengue fever (a mosquito borne disease caused by the dengue virus).  The leaves bark and roots are often sold in local markets and play a fundamental local role in the local treatment and management of numerous kinds of diseases.

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. Combretum collinum Fresen. subsp. suluense (Engl. & Diels) Okafor. National Assessment: Red List of South African Plants version . Accessed on 2024/09/14.

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. Jacana, Johannesburg.

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

http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=558

http://www.mrcindia.org/journal/issues/454321.pdf

http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=141830

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

http://eol.org/pages/5426895/names/common_names

http://www.thaliatook.com/OGOD/collatina.php