General Info – summary

This deciduous Tree with its dense crown and rough, longitudinally fissured, grey to black bark is up to 10m high.  Simple, entire and often hairy Leaves lack stipules and rest on hairy petioles.  The small, white or creamy yellow, bisexual, regular Flowers with inferior ovaries occur in spikes and lack pedicels.  The 8 stamens develop after the stigma and style.  The colourful 4-winged and indehiscent Fruit is one seeded.

Description

Combretum hereroense

Previous Names: Combretum hereroense var. villosisimum, Combretum porphyrolepis, Combretum rhodesicum, Combretum transvaalense.

SA Tree No. 538.

Common names: (Afr) Kierieklapper, Steelboom.  (Eng) Mouse-eared Combretum, Russet Bushwillow: (Russet – dark brown with a red-orange tinge referring to the fruit), Mouse-eared Combretum.  (isiZulu) Umdubu, Umhalalavane.  (Northern Sotho) Mokabi, Mokata.  (Setswana) Mokabi, Mokata.  (siSwati) lsihlalavane, LiVimbela, siHlavane, Umdvubu, Umphulumbu.  (Tshivenda) Mudzwiri, Mugavhi.  (Xitsonga) Mpotsa, Xikhavi.

Family: Combretaceae (Bushwlillow family).  In this family, there are about 16 genera, containing about 530 species.  In South Africa, there are 5 genera and 41 species.  Here the genera with Trees include Combretum, Lumnitzera, Pteleopsis and Terminalia.  The simple and usually entire Leaves lack stipules.  Flowers are usually bisexual, usually with 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 can be winged or ridged.

Name derivation: Combretum – climbing plants.  hereroense – named after the Herero people of Namibia (250 000 in 2013), Botswana and Angola.  They speak Otjiherero.

Conservation Status:  http://redlist.sanbi.org/ – here no data available.  However, it appears to be widespread and not threatened.  The IUCN Red List (2019) classifies it as Least Concern and Stable.

Tree

This Tree (photo 495) may reach 7m or more in height and is usually single stemmed but may be multi-stemmed.  The Trunk is often crooked.  The rough Bark is light to dark grey or black, longitudinally furrowed and flakes in narrow strips (photos 510 & 539).  These strips become visible as the tree ages.  The light grey to reddish brown Branches often arch upwards (photo 495).  The initially hairy branchlets (photo 499 – under Leaves) become smooth and hairless.  The dense Crown is usually rounded in isolated trees (photo 568).

Leaves

This deciduous or semi deciduous tree has shiny Leaves resembling mouse ears which are dark to grey green above, paler and covered with velvety brown hairs below (especially young leaves) making the whole tree slightly brown.  They may also be almost hairless.  Leaves are opposite, or nearly so, often arise on short side shoots (photos 553 & 499) and are simple (have a single blade, which may have incisions that are not deep enough to divide the leaf into leaflets).  Each leathery leaf is elliptic/broadly elliptic or oval to obovate.  Size varies (7) 3 x 2 (4,50) cm (photo 502).  In autumn, leaves turn a coppery/purplish colour.  The short tapering, even notched Apex may be incurved (photo 502), may end in a short sharp tip (photo 499) or is apiculate (ending in a short, sharp, flexible point – photo 499).  The Base is tapering to rounded.  The Midrib and lateral veins are sunken above and protrude below – where they are clearly visible.  Here the 3-6 pairs of side veins are often hairy and arch and join with others, prior to reaching the margin.  All veins are clearly visible if the leaf is examined against the sun with the aid of a hand lens (photo 505).  The rolled under Margin (photo 499) may be slightly wavy and is entire (with a continuous margin, not in any way indented).  The reddish-brown Petiole (leaf stalk) is often hairy and up to 0,6cm long (photo 502).  Stipules (basal appendages of the petiole) are absent.  Red Scales may be visible on the lower surface.

Flowers

The small, white or creamy to yellow, scented Flowers are arranged in dense axillary – photo 541 or terminal Spikes (simple, indeterminate inflorescence with sessile flowers on a single unbranched stalk – photo 561).  The individual open spike may be almost spherical (photo 561) up to 30cm long and may appear in axils of leaf scars.  Flowers may appear before (usually) or with the new leaves.  The bisexual flowers are actinomorphic (Regular, symmetrical.  Flowers are vertically divisible into similar halves by more than 1 plane passing through the axis).  The green Sepals are shorter than the small protruding, very thin white Petals (photo 562).  The 8 exerted Stamens are in 2 whorls and have versatile (hung or attached near the middle, and usually moving freely) Anthers that are dorsifixed.  There is a single Pistil (a unit of the Gynoecium, the female element of the flower, composed of the Ovary, Style and Stigma).  When viewed closely, each flower appears to have a Pedicel (flower stalk).  This is not the case.  What is visible is the completely inferior Ovary giving the impression that that the flowers are stalked (photo 562).  Also visible here, on the upper spike of younger flowers, are the Stigma and Style, which emerge before the Stamens.  (Sep-Nov).

Fruit

The small and very attractive 4-winged Fruit is a Samara (a dry, indehiscent winged fruit, with papery wings, that develop from the ovary wall.  The numerous fruits are conspicuous in both number and size.  The fruit may be slightly longer and is usually about 2,4 x 2cm (photo 509).  The fruit soon develops golden edged wings (photo 507) and an attractive, rich dark reddish-brown centre surrounding the seed.  This turns darker with maturity and may remain on the tree until after the new flowers appear (photo 569).  (Jan-Aug).

Distribution & Ecology

This drought resistant, Afrotropic Tree is common in the bushveld (a sub-tropical woodland ecoregion of southern Africa), often grows in sand and close to streams and rivers in both highveld and lowveld.  It also occurs in shrublands and with termite mounds.  Trees normally occur below 1 500m.  They may be found in stony, shallow and brak soil (alkaline, containing an excess of minerals) as well as sharing open woodland with Colophospermum mopane.  These Russet Bushwillow plants are located in Northern KwaZulu-Natal – here they often grow with Senegalia (Acacia) nigressence. They also occur in Gauteng, North West, Mpumalanga e.g., near Lower Sabi KNP, Swaziland, Namibia, Botswana, Zimbabwe, widespread in Mozambique and northwards into tropical Africa – including Kenya and Somalia.  Nocturnal, Lesser Bushbabies (with big eyes, long tails, large naked and mobile ears), consume small invertebrates and Gum (possibly poisonous) from wounds.  Elephant, giraffe, kudu, steenbuck, duiker and impala graze the Leaves.  Puffback (Dryoscopus sp.) and other local shrikes are among the birds that are attracted by the insects that pollinate the flowers or eat the fruit.

Ethnobotany

The reasonably dense Wood is hard, brown and has dark markings.  It is termite and borer resistant and produces a good finish.  Wood is used to make implement handles like pick and hoe handles as well as knobkerries (using the connection of big and small branches).  The wood is an excellent fuel – producing long-lasting coals.  The Tree also makes a good bonsai.  Leaves provide a useful cattle fodder and are used to make tea in Zimbabwe.  Seed germination rate is low and young plants should be protected against frost.  Prior to planting, the seeds must be removed from the samara.  This slow growing plant does best in sunny or semi-shaded places in sandy or loamy soils.  This plant makes a good bonsai.  Local medicine makes use of this plant.

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 (Pty) Ltd, Cape Town.

Ginn P.J. Mcilleron W.G. and Milstein P. le S, 1989. The Complete Book of Southern African Birds. 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. Jacana, Johannesburg.

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

 

http://redlist.sanbi.org

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

http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=141930

http://operationwildflower.org.za/index.php/albums/genera/combretum/combretum-hereroense-thabo-1-1560

http://iscantree.co.za/combretum-hereroense-kierieklapper-russet-bush-willow/

https://www.iucnredlist.org/search?query=Combretum hereroense&searchType=species

 

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

http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=141930

http://operationwildflower.org.za/index.php/albums/genera/combretum/combretum-hereroense-thabo-1-1560

http://iscantree.co.za/combretum-hereroense-kierieklapper-russet-bush-willow/

https://www.iucnredlist.org/search?query=Combretum