Gahnia aspera subsp. globosa is a perennial plant characterized by its erect to ascending rhizomes, which are clothed with the brown to dark brown remains of basal sheaths. The species forms tufted culms 25 to 40 cm tall and 3 to 6 mm in diameter at the lower part, typically with one or two nodes between the base and the inflorescence. Its leaves are primarily basal, with only one or two being cauline, and the leaf blades are linear, ranging from 60 to 90 cm in length and 6 to 13 mm in width, with some being shorter than nearly as long as the culm. The leaves feature acuminate apices, coriaceous textures, and serrulate-scabrous margins that are strongly involute. The inflorescence is a dense, spike-like panicle, oblong-ovoid or oblong-ellipsoid in shape, 7 to 15 cm long and 2.5 to 5 cm in diameter, with 5 to 7 partial panicles closely borne. Flowers can be either bisexual (perfect) or staminate, with dark brown glumes and a perianth usually consisting of two small scales. The fruit is an oblong-obovoid, trigonous achene, 1.2 to 1.5 mm long. The seeds are 1 per fruit; seed coat thin; free from pericarp; embryo basal; endosperm abundant. It typically grows in mesic forests, often on open ridges, at elevations ranging from 310 – 610 meters.