Chaenostoma is a genus of flowering plants belonging to the family Scrophulariaceae. Its native range is Southern Tropical and Southern Africa. The genus name, Chaenostoma, means gaping mouth.

Chaenostoma subnudum, synonymously known as Sutera stenophylla or Sutera subnuda is a South African endemic species from the Western Cape Province. Chaenostoma subnudum is a perennial, wiry shrublet that grows to 50 cm. Its leaves are opposite, linear to lanceolate, long and narrow with the margins rolled under. The flowers are mauve-pink with a funnel-shaped orange throat from which the four stamens protrude notably. The five petals have rounded tips and parallel sides. Flowering can be seen in spring and summer.