Oreostylidium subulatum is a very small, cæspitose, and densely tufted plant about 2–3 cm tall. The 2 cm long linear-subulate leaves form a basal rosette close to the ground.
In terms of its physical characteristics, Oreostylidium subulatum is a small, densely packed plant with linear, pointed leaves forming a rosette close to the soil surface.