Cyperus thunbergii Vahl

Perennial herb, robust, tufted, 0.35-2.00 m high. Leaf blades 5.5-12.2 mm wide, V-shaped, margins serrated. Culm scapose, 3-angled, 2.9-10.5 mm in diam. Inflorescence a large, compound anthela of 6-13 often compound spikes, the largest long-cylindrical, 24-46 x 10-16 mm. Subtending bracts 5-14, leaf-like. Spikelets very densely crowded, compressed, linear to narrowly elliptic, 5.1-8.1 x 0.9-2.5 mm, 2-5-flowered. Glumes imbricate, ovate when flattened, 2.9-6.5 mm long, keel nonexcurrent or excurrent into small point. Flowering time Sept., Oct., Jan. Nutlet narrowly elliptical, 1.8-2.7 x 0.5-0.7 mm, 3-angled, brown, surface puncticulate or minutely reticulate.