Drosera bulbigena is one of the smallest tuberous sundews, with an erect stem that grows up to a few cm in height. The species is named after its propensity to form adventitious tubers (bulbus = bulb, genus = offspring).

Drosera bulbigena has a self-supporting stem that grows 3-6 cm in height. The stem is glabrous and gently zigzagging, switching directions at every leaf node. The petioles bend downwards at the connection with the lamina, facing the lamina in a downward direction. This connection is near the top of the lamina. The laminae are crescentic, with a notch on the top edge. The flowers are white. The sepals are glabrous with fimbraite margins.

The species grows in seasonally wet moss, sandy or clayey substrates at the margins of swamps. It is found in the Swan Coastal Plain.

The diminutive size and downwards-facing laminae are unique for the species. Its closest relative is Drosera radicans, which grows north of Geraldton, is double the size and does not have downwards pointing leaves.