The almost white Monsonia crassicaulis flowers seen blooming here in the Karoo Desert National Botanical Garden may sometimes be a shade more creamy yellow.
The flowers are from about 3 cm to 5,5 cm in diameter. Spring and summer blooming characterises the plant, when rain permits. The photo was taken in mid-August (Le Roux, et al, 2005).
(Also see the entries about this plant on this Site in the Monsonia and Namaqualand Albums.)