Piaranthus geminatus subsp. geminatus stem tip bud

This photo taken near Oudtshoorn shows the purple Piaranthus geminatus subsp. geminatus flower stalk carrying a bud protruding from a stem tip. 

Piaranthus flowers grow thus from a stem tip or in some species from somewhere along the length of the stem, while Huernia flowers emerge from near the stem base. The acuminate (tapering) sepals are still nearly closed over the corolla in picture.

Curving white tips of some stem tubercles are visible (White and Sloane, 1937; Vlok and Schutte-Vlok, 2010).