This is the darker flowering Brachystelma swazicum. The five spreading corolla lobes are beyond deep purple, nearly black. Their margins curve in elegantly to the pointed tips. The yellow and white flower centre where the two coronas and staminal column are situated appears similar to the centres of the flowers that bear reddish corolla lobes.
The pale green leaves have slightly coarse surfaces, here with distinct, smooth midribs and only few, spaced lateral veins, at least visible in the central parts of the leaves. The margins are entire but the sparse white stubble is the notable feature. Similar stubble is visible on the fleshy red stem part in picture (Smith, et al, 2017; iNaturalist).