The old flowers of Grewia robusta are paler than newly opened ones. There is a white form of the plant and there may be a recently discovered white-flowering species in the west of the Little Karoo.

The sepals in picture taper to pointed tips, the broader petals above and alternating with them have more rounded and shallowly, irregularly scalloped tips.

Some anthers are lost by now, while some filaments are curving out more (Vlok and Schutte-Vlok, 2015; Shearing and Van Heerden, 2008; Coates Palgrave, 2002; iNaturalist).