Drosera citrina is a pygmy sundew endemic named for its lemon-yellow flowers (citrinus = lemon coloured).

Drosera citrina is a small sundew with a rosette of many low-lying leaves around 1.5 cm in diameter. The flowers are pale yellow on the outer half and white on the inner half. The styles are rather long and thin, and coloured white. The flower stalk is moderately covered in small glands. The stipular bud formed towards the end of its growing season is broad and distinctly low-lying.

The species is restricted to deep yellow-coloured sand near Regan’s Ford north of Perth. It grows under the shelter of shrubs in heathland. The species blooms in early to mid-spring, and is dormant over summer.

Drosera citrina is closely related to Drosera nivea, sharing similar floral and foliage morphology as well as a requirement for deep yellow sand. The flowers of Drosera citrina are generally yellow, whereas those of D. nivea are generally white (although both species can have the reverse colour). Drosera citrina is distinguished by its flatter stipular bud (that of D. nivea is more pointed towards the middle). Drosera citrina is found in more southerly locations relative to D. nivea.

Drosera coalara is another taxon that is closely related to both D. citrina and D. nivea. Kruger and Fleischman (2020) contend that D. coalara represents morphological and geographical intermediates that link the predominantly yellow-flowered D. citrina in the south to the predominantly white flowered D. nivea in the north.