Drosera collina is a large rosetted tuberous species endemic to Western Australia. It can be distinguished from other members of the Drosera erythrorhiza complex, its numerous leaves (typically 10-12), which are elongated in shape. The plants usually start of green and may achieve a reddish tinge towards the end of the growing season. It’s specific epithet references its hilly habitat in the lightly shaded jarrah forest of the Darling Scarp.
Drosera erythrorhiza is distinguished from Drosera magna and erythrorhiza by the shape of its leaves, which are long and oval. It does not form dense clonal colonies, and grows in groups of one to two plants. It is somewhat similar in shape to Drosera squamosa, but lacks its bright red margin. Small differences in the floral structure also distinguish the two species apart.