Pterocarpus angolensis

Pterocarpus angolensis
Kiaat seed in autumn, photographed in Matabeleland South, Zimbabwe
Yellow flowers
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Fabales
Family: Fabaceae
Subfamily: Faboideae
Clade: Dalbergioids
Tribe: Dalbergieae
Genus: Pterocarpus
Species:
P. angolensis
Binomial name
Pterocarpus angolensis

Pterocarpus angolensis (African teak, wild teak, Portuguese: Girassonde, Afrikaans: Kiaat, Sotho: Morôtô, Tswana: Mokwa, Venda: Mutondo, Shona: Mukwa, Ndebele: Umvagazi,[2] Shona: Mubvamaropa, Zulu: Umvangazi)[3] is a species of Pterocarpus native to southern Africa, in Angola, Mozambique, Namibia, South Africa, Eswatini, Tanzania, Democratic Republic of the Congo, Zimbabwe, and Zambia.[4] It is a protected tree in South Africa.[3] The name Kiaat, although Afrikaans, is sometimes used outside South Africa as well. In Zimbabwe, depending on what region you are in, it is known as Mukwa( which it is also called in Zambia) or Mubvamaropa.

Description

Kiaat tree at the Pretoria National Botanical Garden
Red blood-like sap
Developing pod

It is a deciduous tree usually growing to 16 m tall, with dark brown bark and a high, wide-crowned canopy of shiny compound leaves. In favoured wetter locations the trees are typically about 18–19 m tall. The leaves appear at the time of the flowers or shortly afterwards. They are alternate, deep green, imparipinnate, with 11-19 subopposite to alternate leaflets, the leaflets 2.5–7 cm long and 2–4.5 cm broad. It produces an abundance of scented, orange-yellow flowers in panicles 10–20 cm long; flowering is in the spring. In southern Africa, this is usually just at the end of the dry season, often about mid-October. The pod is 2–3 cm diameter, surrounded by a circular wing 8–12 cm diameter, reminiscent of a brown fried egg, and containing a single seed. This brown papery and spiky seed pod stays on long after the leaves have fallen. In poorly drained locations, the tree can still grow but it becomes more open in shape with leaves on the end of long branches - a 'stag-headed' appearance.[5][6] It is referred to as a blood wood tree: when it is cut, it appears to bleed because of dark red sap.[7]

Ecology

Pterocarpus angolensis grows in southern and eastern Africa over a wide range of localities where there is a dry season contrasting with a wet season. It grows best where it is warm and free of frost. The soil type must be deep sandy soil or well drained rocky slopes where the rainfall is above 500 mm per year. It grows well in areas of open woodland such as the Mashonaland plateau in Zimbabwe and northern Kwazulu-Natal region of South Africa, where it assumes a broad crown with heavy branches, and is a pioneer species on woodland and forest margins. The best specimens grow in the seasonal closed woodland of central Mozambique and parts of Malawi, where they sometimes form pure stands.[5]

Pterocarpus angolensis is fed upon by many animals that include the charaxes butterfly in larval state, squirrels, baboons and monkeys that feed on the seed pods, which have a diameter of about 12 cm. The elephant has been known to destroy P. angolensis by pushing it over.[5]

Uses

Reddish Kiaat plank

There are several uses for the wood of P. angolensis. The brown heartwood is resistant to borer and termite, is durable and has a pleasing spicy fragrance. The wood polishes well and is well known in tropical Africa as Mukwa when used to make good quality furniture that has an attractive light brownish-yellow colour. It can also be used for curios, and implements. Since the wood does not swell or shrink much it is great for canoe building. Furniture and curios are often made from the reddish sapwood. The colour of the sapwood is a result of the remarkable, dark red sap of the plant; an alternative name of Bloodwood rises from this. This wood also produces a rich, resonant sound and can be made into many different musical instruments.[5] In Zimbabwe, the mbira is traditionally made from mukwa.

Methanolic extracts of the bark have been reported to have molluscicidal activity against some freshwater snails.[2] The resemblance of the sap to blood has led to the belief in supposed magical healing powers concerning the blood. Because of all these reasons and that it is also fire resistant, P. angolensis is sometimes planted around the chief's enclosure to make a living fence.[5]

References

  1. ^ Barstow, M.; Timberlake, J.R. (2018). "Pterocarpus angolensis". IUCN Red List of Threatened Species. 2018: e.T33190A67802808. doi:10.2305/IUCN.UK.2018-1.RLTS.T33190A67802808.en. Retrieved 19 November 2021.
  2. ^ a b Ndabambi, M; Basopo, N; Nkiwane, Lc; Naik, Ys (2015-01-02). "The molluscicidal efficacy of methanol extracts of Pterocarpus angolensis, Sclerocarya birrea, Pappea capensis and Commiphora africana against Lymnaea natalensis and Helisoma duryi". African Journal of Aquatic Science. 40 (1): 107–108. doi:10.2989/16085914.2015.1024605. ISSN 1608-5914. S2CID 84875010.
  3. ^ a b "Protected Trees" (PDF). Department of Water Affairs and Forestry, Republic of South Africa. 3 May 2013. Archived from the original (PDF) on 5 July 2010.
  4. ^ International Legume Database & Information Service: Pterocarpus angolensis
  5. ^ a b c d e Coates Palgrave, K. (1983). Trees of Southern Africa. Struik Publishers.
  6. ^ Danida Seed Leaflet: Pterocarpus angolensis (pdf file)[permanent dead link]
  7. ^ Van der Riet, K.; Van Rensburg*, L.; De Sousa Correia, R.I.; Mienie, L.J.; Kruger, G.H.J. (17 June 1998). "Germination of Pterocarpus angolensis DC. and evaluation of the possible antimicrobial action of the phloem sap". S. Afr. J. Plant Soil. 15 (4): 141. doi:10.1080/02571862.1998.10635132. Retrieved 18 May 2022.
  • "Pterocarpus angolensis". PlantZAfrica.com. Retrieved 2010-02-09.
  • van Wyk, B. and van Wyk, P. 1997. Field Guide to trees of South Africa. Struik, Cape Town

External links