Chaetacme aristata (Thorny elm)

[= Chaetachme aristata]

Basterwitpeer [Afrikaans]; umKovoti [Xhosa]; umKhovothi, umBambangwe ("it catches the leopard") [Zulu]; umBangabangwe [Swazi]; mula-nguluvhe ("wild pig fodder") [Venda]

Life > eukaryotes > Archaeoplastida > Chloroplastida > Charophyta > Streptophytina > Plantae (land plants) > Tracheophyta (vascular plants) > Euphyllophyta > Lignophyta (woody plants) > Spermatophyta (seed plants) > Angiospermae (flowering plants) > Eudicotyledons > Core Eudicots > Rosids > Eurosid I > Order: Rosales > Family: Ulmaceae

Chaetacme aristata, National Botanic Garden, Harare, Zimbabwe. [photo Julian Spurway ©, Flora of Zimbabwe]

Identification

• A shrub or small tree, growing to a height of 15 m, generally with dense foliage and often coppicing from the base.
• Leaves are alternate and there are usually one or two straight spines in the leaf axil. Branchlets zigzag between leaf/spine nodes. Leaves are simple, more or less elliptical, and have a characteristic hair-like bristle at their tips; leaf margins can be smooth or sharply toothed.
• The bark is pale grey and the trunk is often fluted at the base. The trunk often has spines or vestiges of sharp-tipped branchlets with spines.
• Flowers are unisexual, in axillary cymes, greenish or cream, blooming from late winter to early summer.
• Fruit is spherical, about 15 mm in diameter and pink, yellow or orange in colour.

Distribution and habitat

Native to Africa south of the Sahara, and Madagascar. Within southern Africa is is found in the Western Cape (from Knysna eastwards), Eastern Cape, KwaZulu-Natal, Limpopo, Mpumalanga, Northwest Province, Gauteng, Swaziland, Zimbabwe, Mozambique and eastern edge of Botswana. Found in coastal and riverine forest, in wooded kloofs and along bushveld streams.

Ecological interactions

• Fruit are eaten by:
  • birds (according to Palmer & Pitman [1972], with the exception of the following two species, birds are not particularly fond of the fruit):
    • Amblyospiza albifrons (Thick-billed weaver) 
    • Gallirex porphyreolophus (Purple-crested turaco, Purple-crested lourie) 
• Leaves are eaten by:
  • Tragelaphus angasii (Nyala)
  • Diceros bicornis (Hook-lipped rhinoceros, Black rhinoceros)
• The bark is eaten by:
  • Diceros bicornis (Hook-lipped rhinoceros, Black rhinoceros)

Uses

• The yellowy-coloured wood is hard, heavy, strong and tough and is difficult to chop with an axe. It is not used much.

Links

• Chaetachme aristata Planch. (Flora of Zimbabwe)

References

• Palgrave, K.C. and Palgrave, M.C. 2002. Trees of Southern Africa. 3rd Edition. Struik Publishers, Cape Town.
• Palmer, E. and Pitman, N. 1972. Trees of Southern Africa covering all known indigenous species in the Republic of South Africa, South-West Africa, Botswana, Lesotho and Swaziland. Volume 1. A.A. Balkema, Cape Town.
• van Wyk, B. and van Wyk, P. 1997. Field Guide to Trees of Southern Africa. Struik Publishers, Cape Town.

Text by Hamish Robertson