Mundulea sericea

General Info – Summary

This Tree is usually up to 7m high.  Bark becomes deeply furrowed and corky.  Young branches have silvery white hairs.  Alternate & imparipinnate Leaves have well-spaced leaflets with petiolules.  Pea-like, bluish zygomorphic Flowers develop in racemes.  9 joined and 1 free stamen surround a pistil with an ovary having an incurved style and a capitate stigma.  Fruit is a tardily dehiscent linear pod with reniform seeds.

Description

Previous Names: Mundulea suberosa, Cytisus sericeus, Tephrosia suberosa.

SA Tree No. 226.

Common names: (Afr) Blou-ertjieboom, Blou-ertjieboom, Kurkbos, Mangaanbos, Olifantshout, Visboontjie, Visgif.  (Eng) Cork Bush, Rhodesian Silver Leaf, Silver Bush.  (isiZulu) Umamentabeni, Umhlalantethe, Umsindandlovu, Usekwane.  (Northern Sotho) Mosita-tlou.  (Setswana) Ntsandzandlopfu.  (siSwati) Umsindzanlovana.  (Tshivenda) Mukunda-ndou.

Family: Fabaceae or Leguminosae.  (Pea, bean or legume family).  After the Orchidaceae and the Asteraceae, the Fabaceae is the third largest Angiosperm (flowering plants) family with 700+ genera and close to 20 000 species.  Local Tree genera on this website include Acacia (Vauchellia, Senegalia), Albizia, Bauhinia, Bolusanthus, Burkea, Calpurnia, Colophospermum, Cordyla, Cyclopia, Dichrostachys, Erythrina, Erythrophleum, Faidherbia, Indigofera, Mundulea, Peltophorum, Philenoptera, Piliostigma, Schotia and Xanthocercis.  The Fabaceae are recognisable by their fruit and by their pinnately compound Leaves.  Leaves may also be simple – even bilobed and usually have stipules – some of which may be spinescent.  Leaflets are usually entire.  Flowers are bisexual and bracteate.  Regular flowers usually have 4-5 sepals and the same number of petals.  Irregular flowers have 4-5 sepals and 5 or less petals.  Stamens have anthers that have 2 pollen sacs and there are usually at least twice the number of stamens as petals – often 10.  The superior Ovary has one locule that may contain 1 or more ovules.  The Stigma and Style are simple.  The single carpel develops into the Fruit, which is usually a pod.  This pod dehisces on both sides and may break into segments.  Seeds vary.

Name derivation:  Mundulea – neat, elegant, or named after Johannes Ludwig Leopold Mund (1791-1831).  He was a collector and land surveyor.  He and his wife (a qualified physician) arrived in Cape Town in 1816 and he died there in 1831.  sericea – silky: referring to the hairs on the leaves.  Mundulea sericea is the only species in southern Africa.

Conservation: National Status: L C (Least Concern).  Assessment: 2005/06/30 (W. Foden and L. Potter).

Tree

This plant may be a large woody shrub or a medium sized, tough Tree and is usually up to 5-7m high but may reach 12m.  The single stem has smooth young branches covered with silvery white hairs.  Branches bend like a whip and are difficult to break with bare hands.  The Bark is initially pale grey.  As it ages, it becomes pale, rough and deeply furrowed.  It becomes very corky (photo 291).  The Crown (is the uppermost tree part of the tree and has branches, stems and leaves) is much branched.

Leaves

On this usually evergreen (it may be deciduous) plant, the soft, silvery (mainly below), and delicate Leaves, are in contrast to the very rough trunk.  They are up to 14cm long and have a pale green, grey or silver (due to a dense covering of hairs) appearance.  They differ quite a bit and are up to 10+cm long.  Leaves are imparipinnate (pinnately compound leaf ending in a single leaflet – photos 294 & 300).  The alternate leaves (photo 294) have 4-11 pairs of well-spaced apart and opposite, or nearly so Leaflets (photo 294) and the single terminal one.  The leaflets are up to 6,5 x 2,5cm (photo 300) and are ovate (egg shaped), elliptic or lance shaped.  Margins are widest below the middle.  The margin is entire (with a continuous margin, not in any way indented).  The Rachis (main axis bearing flowers or leaflets) is hairy and grooved along the top (photo 292).  Veins are sunken above and protrude below (photo 300).  The Apex is slightly attenuate (showing a long gradual taper of base or apex in this case) with a usually narrowly rounded apex.  The Base is rounded to broadly tapering.  The hairy Petiole (leaf stalk) is up to 3cm long (photo 300).  Stipules (basal appendage of the petiole) are small and subulate (a part that is slender and tapering to a point).  Petiolules (stalks of leaflets – photo 292) are swollen, hairy and up to 3mm long.

Flowers

The typical pea-like Flowers occur at the ends of branches and are mauve, violet or pink and occasionally white, and usually appear with new-leaves.  They occur in terminal Racemes (simple elongated inflorescence with stalked flowers that open in succession towards the apex) that are up to 14cm long.  Individual flowers have small bracts, are bisexual and zygomorphic (floral parts are unequal in size or form so that the flower is capable of division into essentially symmetrical halves by only one longitudinal plane passing through the axis).  The Calyx is bell-shaped and has a hairy exterior.  The Corolla is made up of 5 Petals: the uppermost is the Vexillum or Standard petal which is externally silky.  Below this, on each side, are the 2-sickle shaped to oblong Wing petals.  Finally, the 2 joined, lowermost petals make up the Keel.  These joined petals are gibbous (swollen or bulging on one side) and are individually similar to the wing petals.  The keel petals surround the 10 uniform Stamens – 9 of which are joined and the tenth, which is dorsally situated below the vexillum, is free.  The Anthers are uniform.  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 subsessile linear Ovary contains a number of ovules.  The incurved Style ends with a small capitate Stigma.  (Oct-Feb).

Fruit

The linear (long and slender) Fruit is a brown or yellowish grey, flattish Pod (a dry, dehiscent fruit – photo 301).  Individually pods are up to 12 x 1cm and tend to hang down in bunches.  Each pod has a marked yellow-brown rim.  Pods may be constricted between seeds.  It is initially velvety golden-brown and ages to grey.  A persistent Calyx and Stigma are visible (photo 301).  The tardily dehiscent pods may remain on the tree for months.  Those that survive into winter tend to look untidy.   Seeds are reniform (kidney-shaped – photo 301) and up to 7 x 4mm.  (Nov-Apr).

Distribution & Ecology

Mundulea sericea is a survivor.  This plant coppices well (when young tree stems are repeatedly cut/burned down to near ground level it can cause regrowth from the stump or roots).  This tree survives frost and heavy rains.  Indigenous locations are in KwaZulu-Natal, Limpopo, Mpumalanga including Kruger NP, Gauteng and North West.  Beyond South Africa it occurs in Mozambique (widespread – especially in the north), Botswana, Zimbabwe, Tanzania, Namibia e.g. Etosha Pan, Angola, Somalia, Madagascar, India and Sri Lanka.  The tree in common in savannah (a rolling grassland scattered with shrubs and isolated trees, which can be found between a tropical rainforest and desert biome) and on rocky koppies (small, natural hills remaining behind from the weathering African veld).  Occasionally the tree occurs near rivers.  These plants usually occur below 1 900m and are common in sandy soil.  The thick, tough and deeply furrowed Bark helps it survive veld fires that may cause the bark to turn black.

Butterfly larvae of the Common Zebra Blue (Leptotes pirithous pirithous) feed on the Flowers and immature Seeds.  This butterfly occurs in Africa, Madagascar, southern Europe and Asia.  This plant also supplies larval food for the Natal Silverline butterfly (Cigaritis natalensis).  Both of these butterflies can initially gain  this nutrition from of Mundulia sericea flowers.  Birds – including sunbirds are attracted to the Flowers.  Bees and Carpenter Bees are agents of Pollination.  Elephants, impala, giraffe and eland browse the leaves.

Ethnobotany

Wood has an unpleasant smell when cut, but it is tough, hard and strong.  Bark and roots can be used as an insecticide.  They may even be used to poison crocodiles.  Roots, bark and seeds are used to poison fish but do not seem to affect grazing animals.  Cooking the collected fish rids it of the poison which contains Rotenone, an insecticide, which is found in many roots including Mundulea sericea.  It also kills spiders.  Other rotenoids including deguelin and tephrosin are present in this plant.  Side effects on mammals are small.  Domestic animals eat the Leaves.  This tree is easy to Grow from seeds which should be soaked in hot water before planting.  They do best in well-drained soil.  The tree is hardy, slows growing and has attractive silvery leaves and flowers.  The roots are non-aggressive.  This plant does well in containers and used in bonsai (Japanese art of growing and shaping miniature trees in containers).  Plants are also used in local medicine).

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. Mundulea sericea (Willd.) A.Chev. subsp. sericea. National Assessment: Red List of South African Plants version 2024.1. Accessed on 2025/11/09.

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.

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

http://www.plantzafrica.com/plantklm/munduleasericea.htm

http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=130100w

https://plants.jstor.org/stable/10.5555/al.ap.person.bm000125930

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