Nelia pillansii flowers grow solitary or in groups of up to three on short pedicels, near the leaves.
The white flowers have stiff petals with variably shaped tips, and hairs at their bases. Once the flowers have opened, they do not close again as many mesemb flowers do at night, these being similar to the altydvygies or erepsias. The flowers tend to last long, and the petals may also remain on the fruit for long. Flower diameter is about 1,5 cm.
Bloomtime is late winter and early summer.
The five-locular fruit capsules are hygrochastic, opening when wet and closing when dry, a widely acquired facility of mesemb species for maximising germination opportunities (Frandsen, 2017; Le Roux, et al, 2005; iNaturalist).