Aulax is a small genus of three species of evergreen shrubs in the family Proteaceae (order Proteales), endemic to South Africa. Known collectively as featherbushes, they are among the most distinctive members of the Cape Floristic Region's extraordinarily rich Proteaceae flora.
The genus stands out within the South African Proteaceae for being dioecious — male and female flowers are borne on entirely separate plants, a trait rare in the family. The shrubs carry fine, needle-like foliage. In spring and summer, female plants produce decorative funnel-shaped flowerheads resembling those of the related genus Leucospermum; these mature into compact seed cones. Male plants bear catkin-like yellow flowers that are less showy but botanically distinctive.
Aulax comprises just three described species: Aulax cancellata (Channel-leaf featherbush), Aulax umbellata (Broad-leaf or Fluffy featherbush), and Aulax pallasia (Needle-leaf featherbush). Like most Proteaceae of the Cape, they are adapted to the nutrient-poor, well-drained soils of fynbos and adjacent shrublands, tolerating extreme heat, low humidity, and extended drought.
Distribution
Aulax is endemic to South Africa, where all three species occur within the Cape Floristic Region — one of the world's biodiversity hotspots and home to a remarkable diversity of Proteaceae.
Cultivation
Featherbushes are tough plants in all respects except frost hardiness. They tolerate extreme heat, very low humidity, and prolonged drought. Like virtually all Proteaceae, they grow best on light, gritty, well-drained soil and should not be planted in rich or waterlogged conditions. Propagation is from seed or half-hardened cuttings taken in late summer to autumn.
Taxonomy Notes
Aulax belongs to the family Proteaceae, order Proteales, and is placed within the subfamily Proteoideae alongside many other Cape Proteaceae genera. It is unusual within the South African Proteaceae for its dioecy — the separation of male and female flowers onto distinct individual plants — a trait that distinguishes it from the closely related Leucospermum and Protea.
