(Cyperus esculentus)
Yellow nutsedge is a warm season, perennial species that is native to Europe. Plants range from 6 to 30 inches tall. Leaves originate from the base of each stem and are grasslike, smooth, glossy, and folded lengthwise. The stems are pithy and triangular in cross-section. The flower inflorescence is umbrella-shaped, has up to 40 florets per flattened spikelet, and is subtended by 3 to 9, long, leaflike bracts. Flowers are yellowish-brown in color and appear from June to October. The root system on each plant can produce hundreds to thousands of hard, round, brown-black tubers in a season; the tubers can survive 3 to 4 years. Yellow nutsedge is particularly noticeable in July and August when it grows more quickly than native species and stands out visually.