Tetradenia is a genus of flowering shrubs in the mint family, Lamiaceae (order Lamiales), commonly known as gingerbush. The genus was first described in 1830 and comprises roughly 20 species distributed across sub-Saharan Africa and Madagascar. Species occur across a wide latitudinal range — from Ethiopia and Sudan in the north, through East Africa and the Congo Basin, to KwaZulu-Natal in the south — with a significant cluster of endemics on Madagascar.
Plants in the genus are aromatic shrubs or subshrubs, a characteristic shared with many members of the Lamiaceae family. The common name "gingerbush" reflects the spicy, resinous fragrance of the foliage. The best-known species is Tetradenia riparia, a fast-growing shrub native to riverine and rocky habitats across southern Africa, which has also become popular in cultivation for its clouds of pale lilac flowers and strongly scented leaves.
Distribution
Tetradenia is native to Africa, with species ranging from Ethiopia and Sudan in the northeast through central and eastern Africa to KwaZulu-Natal in the south, as well as Namibia, Botswana, and Zimbabwe. A substantial portion of the genus consists of endemic species found only on Madagascar.
Taxonomy Notes
The genus Tetradenia belongs to the family Lamiaceae (order Lamiales). It was first described in 1830. Several species were formerly placed in the genus Iboza — the species now accepted as Tetradenia riparia (Hochst.) Codd was long known under the synonym Iboza riparia, reflecting this historical synonymy.
