Cyperus neokunthianus, a member of the Cyperaceae (sedge) family, is a perennial plant with short and slightly thickened rhizomes. Culms (aerial stems) are 40 to 120 cm (16 to 47 in) tall and 2 to 5 mm (0.08 to 0.2 in) in diameter near the base, trigonous (3-sided) and smooth or roughened on angles below the inflorescence. Leaves are basal, crowded, herbaceous to leathery, linear, shorter than or as long as the culm, 2 to 12 mm (0.08 to 0.5 in) wide with flat or curved margins and reddish brown sheaths. Inflorescences are umbelliform, 5 to 7 cm (2 to 2.8 in) long and 8 to 15 cm (3 to 6 in) wide with 8 to 12 rays per spike. Five to 8 basal bracts occur on each culm. Spikelets bear 4 to 6 glumes (bracts) and 3 to 5 fertile flowers, weakly laterally flattened, 5 to 6 mm (0.2 to 0.23 in) long. Achenes (dry fruit) are oblong, trigonous, about 2 mm (0.08 in) long and 0.5 mm (0.02 in) wide.