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