The six broadly elliptic tepals of a Gethyllis namaquensis flower grow in two concentric whorls of three each. The tepals end in acutely pointed tips that angle out before spreading or recurving. They are white and fleshy, sometimes lilac or pink on the outside. Tepal dimensions are up to 5 cm long and 2 cm wide. The flowers are large, up to 8 cm across.
A thickish, off-white to dull yellowish pedicel is visible below one of the flowers in picture. The bulging ovary below that is usually underground, enclosed in the bulb neck.
A small, succulent berry follows flowering as fruit. It is narrowly club-shaped, indehiscent and pale yellow (Duncan, et al, 2016; Williamson, 2010; iNaturalist; https://www.worldfloraonline.org).