Cyperus

Perennial, less often annual, herbs, tufted or with rhizomes or stolons, sometimes producing tubers or bulbs. Culms usually triangular. Leaves usually at or near the base of the culm, the culm base sometimes swollen, 3-ranked, linear and grass-like, the lower ones often scale-like. Inflorescence terminal, often a subumbel-like anthela or congested into a dense head; subtended by leaf-like involucral bracts. Spikelets 1-many-flowered. Glumes distichous. Perianth 0. Stamens 1-3. Stigmas 2-3, if 2, then nutlet dorsally flattened. Fruit a nutlet, usually dorsally flattened.