The golden yellow flower of Fenestraria rhopalophylla subsp. aurantiaca grows long-stalked and solitary or in groups of three. The subspecific name, aurantiaca, refers to the golden flower colour. The spreading, free petals grow in one to a few whorls around the numerous, oblong, yellow stamens. The flower diameter is from 5 cm to 7 cm. The spreading stigmas among the stamens are feathery.
Flowers open around noon, closing by late afternoon. Flowering happens from before midwinter to early spring, only after rain.
The fruit capsule on a slender stalk has from 8 to 16 locules. This stalk breaks off for the capsule to roll away in tumbling fruit manner, enhancing seed dispersal. The closing bodies and valve wings on the flattish fruit capsule are small, the expanding keels parallel and toothed. Closing membranes are present.
The cone-shaped seeds are small and nearly white (Grenier, 2019; Frandsen, 2017; Williamson, 2010; Smith, et al, 1998).