The flowers of Nemesia deflexa grow from upper leaf axils or in loose racemes on long, hairy pedicels. The small calyces consist of five narrow, acutely pointed, hairy lobes that are not quite equal, green or sometimes dark red. There are alternate bracts below the flowers, the lower ones leaf-like.
The two-lipped corollas have four round-tipped, white lobes in their upper lips with parallel dark red striped up the lower parts, while pale at the bases. The lower lips are white, sometimes as broad as the upper lobes combined with bulging yellow ridges below the corolla mouths. The lower lip margins are rounded and shallowly notched in the centre, sometimes wavy laterally.
Each flower has a narrow spur protruding from the back of the corolla, over 4 mm long. The stamens are white. The fruits are compressed, partly wedge-shaped capsules (iNaturalist; https://www.worldfloraonline.org).