Prismatocarpus fruticosus flowers grow solitary or in small groups in leafless, branched inflorescences. The small green calyces are five-lobed. Calyx shape is best shown when the corolla is already lost, as in some cases in the photo. The white or blue corollas are deeply funnel-shaped to about cylindrical, each ending in five spreading, pointed lobes. The tubes are purple or brown on the outside surfaces. The cylindrical ovary is inferior. A flower is up to 1,5 cm in diameter.
Bloomtime is from late spring to after midautumn.
The ripe fruit capsule splits into five strip-like segments (Manning, 2009; Bond and Goldblatt, 1984; Mason, et al, 1972; iNaturalist).