Scientific Name: Cyperus esculentus

Common Name: yellow nutsedge

Other Common Names: yellow nutgrass

Habit: Plants emerge from spring until late summer. Flowers (spiklets) are present from early summer through autumn and tubers are formed late spring through autumn. Sedges thrive in wet conditions and are often more problematic in low-lying wet areas or during years of excessive rainfall.

Leaves: The yellow-green blades are narrow, flat to v-shaped, alternate, and shiny with extremely tapered leaf tips. Leaves can reach 20 cm long and are 4-9 mm wide with a prominent midrib. Does not have auricles or ligules. Leaves gradually taper to a point unlike those of purple nutsedge, which taper abruptly.

Identifying Characteristics: Yellow nutsedge has a triangular three-sided stem and reproduces primarily through tubers and rhizomes. Tubers are formed at the end of rhizomes and can remain dormant in the soil for over 10 years. Yellow nutsedge leaves taper to a point unlike purple nutsedge leaves, which have an abrupt point. Yellow nutsedge plants grow much larger than annual sedges and kyllinga.

Flower Seed Head: Flowers look similar to a grass seed-head and are yellow to brownish in color. The flower stalk is naked and three-sided. Flowers are usually not produced when the plant is mowed at lawn height. Flowers are flattened and approximately 0.5-1 inches in length, yellow, and produced in loose clusters at the end of a 30- to 60-cm stem in clusters.

Seed Fruit: Each seed is encased in a brown triangular fruit called an achene. Achenes are very small. 0.06 in length.

Where Found: This weed typically is established in wet areas and then begins to spread to other areas. It tolerates moderate mowing height. It can infest almost any location lawns, gardens, flowerbeds, and along untended areas such as fence rows or lake shores.

  • Life cycle: perennial

  • Plant type: Sedge

  • Auricle: not present

  • Plant family: Cyperaceae

  • Leaf arrangement: folded in bud

  • Hair surface: no hairs

  • Ligule: none

  • Length: none

  • Root structure: fibrous; rhizomes present

  • Seed head: spike

  • Width: 6 to 15 mm; less than 5 mm

  • Grass stem: triangle