Obovate leaves, about 6-12 per plant, form a basal rosette with some scattered along the stem.

This species generally has one to five scapes and cymose inflorescences that are 13–40 cm long.

S. dunlopianum's distribution ranges from the Mitchell River area in Western Australia east to the Kakadu National Park in the Northern Territory.

Its typical habitats include sandy or black organic soils along creekbanks, near rainforests, or in seepage areas in Melaleuca leucadendra swamps.

S. dunlopianum is most closely related to S. rotundifolium, but differs most significantly by its thickened stem base and growth habit.