Geissorhiza melanthera is a small perennial plant of 14–18 cm high that is assigned to the family Iridaceae.

Each flower has six pale beige perianth lobes, a purple-red ring around a purple red tube and three blackish stamens.

[1] The bee fly Megapalpus capensis is the only species that has been observed visiting the flowers of Geissorhiza melanthera.

Megapalpus capensis is also known to visit several Pelargonium species, all of which have white, cream or pale pink petals with blackish markings and mostly dark anthers.

[2] The species grows in deep sandy soils, on gentle slopes facing south, in an ecosystem called Leipoldtville Sand Fynbos.