Yellow Nutsedge

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CLASSIFICATION

• Scientific Name: Cyperus esculentus L.
• Family: Cyperaceae, Sedge Family

SEEDLING: Two or three leaves emerge from the ground simultaneously. The blades are linear, folded lengthwise, smooth, membranous, light green, and overlapping to form a somewhat triangular structure in cross section. The bud leaves are erect. The sheaths are tubular.

MATURE PLANT: Yellow Nutsedge is an erect perennial sedge and has unbranched stems which are solid and triangular in cross section, frequently growing up to 69 cm tall. It may reach a height of 90 cm. The leafy shoot and rhizomes originate from a basal bulb formed by a swelling of the stem below the soil surface.

Rhizomes growing out from this basal bulb may produce either secondary basal bulbs or underground tubers. The leaves have a prominent midvein and are arranged in three ranks growing from the basal half of the stem. The newer leaves are ascending and may be as long as, or longer than, the stem. The leaf width ranges from 2-15 mm.

The inflorescence is umbel-like, with up to 10 unequal stalks bearing few to many spike-like branches of flattened yellowish brown spikelets. The spikelets are 1-2.8 cm long and 2 mm wide, each spikelet consisting of several flowers. The stalks may be up to 18 cm long but are frequently much smaller. The modified leaves underneath the inflorescence are variable in number and size. The larger modified leaves may be up to 30 cm long and 9 mm wide. The fruit is enclosed in a thin covering.

It is broadest near the apex and gradually tapers to a narrow, rounded base. The fruit is somewhat triangular in cross section with 3 concave sides. The surface of the covering has minute dimples. The color of the fruit ranges from light tan to dark brown.