Dicoma anomala is a highly variable plant characterized by its stiff, sharp-pointed bracts, large flower heads and mauve-white florets surrounded by many white bristles.Description
Dicoma anomala is a prostrate, decumbent or erect perennial herb with an underground tuber. Few to many erect stems arise from a woody rootstock. Stems are thinly covered with hairs. Leaves are simple, alternate, stalkless, linear or narrowly lanceolate, the upper surface glabrous, the lower surface white-hairy. Flower heads are terminal, solitary or in small groups and have stiff, narrow, sharply-pointed bracts and slender, white, mauve, purple or pink tubular florets. The pappus consists of numerous barbellate bristles. Flowering occurs from November to July, with peak flowering in February and March.
The conservation status of Dicoma anomala is Not Threatened (Threatened Species Program, SANBI). However, the plant is widely utilized by people, who should be informed against over-utilization.
Distribution and habitat
Dicoma anomala is widely distributed in sub-Saharan Africa, resulting in pronounced morphological variety. It grows in the summer rainfall areas and occurs in stony grasslands, hillsides or flat grassland and in savanna, on doleritic or sandy soils south of the Sahara, at altitudes ranging from 165 to 2 075 m.
In South Africa it is widely distributed in Limpopo, North-West, Gauteng, Mpumalanga, Free State, Northern Cape and KwaZulu-Natal. It does not occur in the winter rainfall areas of the Western Cape. In KwaZulu-Natal it was mainly recorded from the Tugela Basin, on sandy soils.
Derivation of name and historical aspects
There are about 16 species of Dicoma in southern Africa. Dicoma tomentosa is the most widely distributed in Africa and D. anomala the second widest.
The genus name Dicoma was derived from the Greek words, di meaning two, and kome, meaning tuft of hair, referring to the double row of pappus bristles. The species name anomala is Latin and means irregular or deviating from the normal.
Wind dispersal of seed probably takes place by means of the persistent barbellate pappus.
Uses and cultural aspects
With Afrikaans names such as koorsbossie (translated as fever bush) and maagbossie (stomach bush), it is not surprising that Dicoma anomala is used medicinally.
Root decoctions are administered orally or as enemas to children believed to be suffering from blood disorders. The root decoctions are used as a purgative for intestinal worms, colic, diarrhoea, dysentery, toothache, as an ingredient for sterilization medication and for haemorrhoids. The root decoctions are also mixed with plants called melkbos for fever, hence the Afrikaans name koorbossie.
Plants parts of Dicoma anomala are said to be used for coughs and respiratory complaints. Roots are sometimes chewed by the Xhosa to induce vomiting when there is suspicion that poisoned food has been ingested.
In animals, the root decoction is used for gall sickness, while powdered plants are used for sores and wounds.