Aristea is a genus of approximately 57 species of evergreen, perennial, rhizomatous flowering plants belonging to the family Iridaceae, in the order Asparagales. The genus was first formally described by William Aiton in 1789, published in Hortus Kewensis.
Plants in this genus are characterised by their grass-like, sword-shaped (ensiform) leaves arising from rhizomes, and their typically blue to violet, six-tepalled flowers borne on branched or unbranched stems. The flowers are generally short-lived, opening for only a few hours, and are arranged in spike-like inflorescences. The stems are often flattened or winged in cross-section, a feature that distinguishes several species.
Aristea is distributed primarily across sub-Saharan Africa, with the greatest diversity centred in the Cape Floristic Region of southern Africa. The genus also extends through tropical East and West Africa and into Madagascar. Notable members include Aristea ecklonii, a widely grown ornamental valued for its prolific blue flowers, and Aristea capitata (blue afrikaner), a robust Cape species with striking deep blue blooms. Aristea africana is one of the most widely recognised species of the Cape flora.
Etymology
The genus name Aristea is derived from the Greek word arista, meaning "awn" — a reference to the pointed, awn-like tips of the leaves or floral bracts characteristic of many species in the group.
Distribution
Aristea is native to tropical and southern Africa and Madagascar. The centre of diversity lies in the Cape Floristic Region of South Africa, though species occur across a broad range spanning East Africa, West Africa, and the island of Madagascar.
