Oscularia comptonii

Of the 22 recognised species of Oscularia only two are reported to have white flowers. The “default“  colour is (light to dark) pink.
O. comptonii forms an erect shrublet to 25 cm tall, with more or less crescent-shaped, keeled leaves to 40 mm long.
The flowers are white to pale pink and up to 27 mm in diameter; they appear from August to October.
The plants occur on sandstone outcrops in and around the Olifants River Valley.

Pictures taken 23 Aug. 2016, just south of Clanwilliam.