Margaritaria discoidea explained

Margaritaria discoidea is a tree in the family Phyllanthaceae, commonly known as the pheasant-berry, egossa red pear or bushveld peacock-berry. These trees are native to the warmer, higher rainfall areas of Africa.

Taxonomy

This species has a complex taxonomic history with many synonyms (see taxobox); partially because of its morphological variability. These trees were formerly placed in the genus Phyllanthus and in the family Euphorbiaceae. 4 varieties are now recognized (1981), these having in the past been treated variously as distinct species, subspecies or synonymous with typical M. discoidea.[1] In KwaZulu-Natal, South Africa, there are 3 varieties:[2]

Distribution

This species is distributed from the coastal areas of the Eastern Cape,[2] South Africa, to tropical Africa,[2] [3] as far as Senegal in West Africa.[3]

Description

A medium to tall tree in forest and riverine situations,[2] where it can grow up to 30 m tall,[4] or a shrub or small tree in dryer and more open situations.[2] The stem is usually straight with rough, flaking bark which is grayish-brown on top and reddish beneath.[2] [5] [6] The branches of young trees grow horizontally from the stem.[2] The leaves are alternate and produced on one plane. Male and female flowers are produced on separate trees, with both types of flowers being small, greenish-yellow in colour,[2] and fragrant.[7] The fruit is a three-lobed capsule about 10 mm in diameter and golden-brown when ripe.[2] The inner part of the fruit is dark metallic blue-green;[5] giving rise to the name bushveld peacock-berry.

Medicinal use

Scientific investigation

These trees contain many alkaloids including phyllochrysine (a central nervous system stimulant) and securinine.[3] [8] [9] Oral administration of an aqueous extract at various concentrations showed no acute toxicity in rats and no adverse change in behavior; suggesting that it may be safe for pharmacological uses. The aqueous extract of M. discoidea stem bark was investigated for its anti-inflammatory and analgesic activities in animal models (rats): The extract reduced significantly the formation of oedema induced by carrageenan and histamine, and had a good analgesic effect, with the results comparable to those of indomethacin, the reference drug used in the study.[4]

In traditional medicine

These trees are used in traditional medicine across Africa: A leaf-decoction is taken in Ivory Coast for blennorrhoea and for poisoning,[10] while in Ubangi a decoction of roots and leafy twigs is also used for blennorrhoea[11] A wash of the decoction is a stimulant in case of general fatigue.[10] The bark is used as a purgative in West Africa and anthelmintic in Central Africa.[8] [12] The Fula people use the bark for toothache, in the Central African Republic a decoction is used for post-partum pains, and in the Republic of the Congo for stomach and kidney complaints and to facilitate parturition.[4] In Malawi the powdered bark extract is applied to swellings and inflammation for quick relief.[13]

Other uses

As fodder

The dried leaves can be used as a food supplement for sheep.[14]

Forestry and timber

The wood is hard and durable and the trees are fast growing from seed,[2] suggesting that this species may be suitable for agroforestry. The sap-wood is yellowish, and the heartwood is pinkish-white to brownish-red, hard, heavy, of medium texture, not difficult to work and is suitable for cabinetry; finishing smoothly and taking a fine polish.[7] The wood can be sawn into planks and used for ordinary building purposes.[7] These trees have been planted in mixed plantations, with a suggestion that they may have a rotation time of 40 to 60 years.[15]

As an acaricide

Extracts from this plant can be used to kill ticks, including Rhipicephalus appendiculatus and Amblyomma variegatum, and an application of a 50% concentrated oil extract on rabbit ears caused a complete inhibition of attachment by adult R. appendiculatus and A. variegatum for at least 4 days.[16] When applied on ticks on cattle in the field, the 50% oil extract induced 100% and 50% mortalities in adult R. appendiculatus and A. variegatum, respectively, by 2 days post-application.[16]

Ecological significance

The leaves are eaten by the larvae of the scarce forest emperor butterfly (Charaxes etesipe tavetensis).[5] The flowers are much visited by bees and other insects. The seeds are a relished food of guineafowl and francolin. Seed in Kenya have attracted bushbuck.[17] M. discoidea is also eaten by red duiker.[18]

Notes and References

  1. 10.2307/4113603 . 219–221 . Radcliffe-Smith, A . Notes on African Euphorbiaceae_ XI_ Margaritaria discoidea_ A Re-Appraisal . Kew Bulletin . 36 . 2 . 1981 . 4113603 .
  2. Book: Pooley, E. . 1993. The Complete Field Guide to Trees of Natal, Zululand and Transkei . 978-0-620-17697-2.
  3. Book: Burkill, H.M. . 1994 . The useful plants of west Tropical Africa . Royal Botanical Gardens, Kew. . London, UK . 978-0-947643-56-0.
  4. Adedapo AA, Sofidiya MO, Afolayan AJ . Anti-inflammatory and analgesic activities of the aqueous extracts of Margaritaria discoidea (Euphorbiaceae) stem bark in experimental animal models. Revista de Biología Tropical. 57. 4. 1193–200. December 2009. 20073344.
  5. Book: Van Wyk . B. . Van Wyk. P. . 1997. Field guide to trees of Southern Africa . 2 . 978-1-86825-922-9.
  6. Book: Woodhall, Steve . Field Guide to Butterflies of South Africa . 2005 . Cape Town, South Africa . Struik . 978-1-86872-724-7 .
  7. Entry for Margaritaria discoidea (Baill.) Webster [family EUPHORBIACEAE]]. dead. https://archive.today/20130801230810/http://www.aluka.org/action/showMetadata?doi=10.5555/AL.AP.UPWTA.2_222&pgs=. 2013-08-01.
  8. Book: Kerharo . J. . J.G. . Adam . 1974 . La Pharmacopie Senegalese traditionelle. Plants medicinales et Toxiques . Vigot Freres . Paris, France.
  9. Weenen et al, 1990
  10. Adjanohoun & Aké Assi, 1972
  11. Portères, s.d.
  12. Watt & Breyer-Brandwijk, 1962
  13. Book: Irvine, F.R. . 1961 . Woody plants of Ghana . Oxford University . London, UK.
  14. Osakwe. I.I. . Steingass. H. . Quantitative Protein And Fat Metabolism In West African Dwarf Sheep Fed Margaritaria Discoidea As Supplement. Animal Research International . 1 . 1 . 2004.
  15. Book: Plant Resources of Tropical Africa 7(1): Timbers 1 . D. . Louppe . A.A. . Oteng-Amoako . M. . Brink . 2008 . 333 . 978-3-8236-1541-5.
  16. 123–129 . 10.1080/01647959508684052 . Acaricidal activity of Margaritaria discoidea (Euphorbiaceae) plant extracts against the ticks Rhipicephalus appendiculatus and Amblyomma variegatum (Ixodidae) . 1995 . Kaaya . Godwin . 2 . Mwangi . Esther . Malonza . Mutua . International Journal of Acarology . 21 .
  17. Book: Eggeling . W.J. . Dale . I. R. . 1952 . The indigenous trees of the Uganda Protectorate . Government Printer . Entebbe . 491.
  18. Van Eeden, D.G. 2006.