Nemesia caerulea spreading its flowers

This blue-flowering plant or these blue-flowering plants may be Nemesia caerulea, photographed near the Sani Pass. Small groups of flowers are paraded boldly, long-stalked among hanging grass on their shared, steep, rocky perch.

The plant resembles N. denticulata. Yellow bosses present or absent at the bases of the corolla lower lips seem to cause confusion in the separation of the two species (Manning, 2009; Pooley, 1998; Wikipedia; iNaturalist).