Low nutrush is a graminoid, 2-6dm tall, with very slender stems and smooth, lanceolate, keeled scales. It has an inflorescence of 2-8 short, capitate cymes each 2-4 mm, sessile, subtended by inconspicuous 4-7mm bracts, forming an erect interrupted spike, anthers are 1mm. Achenes are white, subglobose, 1mm thick, conspicuously apiculate, and verrucose or transversely ridged. Constricted below to a short smooth hypogynium. Its main blades are 1mm wide and often tufted. Sheaths are usually long-villous.
Its flat, very low, unlobed hypogynium distinguishes it from similar species.