Ricefield bulrush
(Schoenoplectus mucronatus )

Description:
Culms triquetrous, 50–100 cm high, 2–8 mm diam.

Leaves reduced. Inflorescence head-like, with 3–25 spikelets, or occasionally proliferating and with a few pedunculate spikelets; involucral bract 1–10 cm long, c. twice as long as inflorescence. Spikelets oblong-ovoid, acute, 10–20 mm long, 4–6 mm diam. Glumes acute, mucronate, 3.5–4 mm long, striate, glabrous, pale red-brown to pale yellow-brown. Hypogynous bristles 5 or 6, retrorsely scabrous, unequal, slightly longer than nut. Style 3- (or 2)-fid.

Nut broad-obovoid, plano-convex or trigonous with indistinct dorsal angle, 1.7–2.2 mm long, 1.5–2 mm diam., slightly rugulose to smooth, dark brown to black, shining.

Flowering: spring–summer.

• Mechanical: Hand-pulling can be labor instensive but a viable means to reduce the populations.
• Biological: Non known
• Herbicide: It can be chemically controlled in ricefields using other foliar herbicides such as glyphosate in combination with drill-seeded rice, which allows the waterl evel to be lowered without harming the rice.

For More Information:
Detailed information about noxious weeds is available at the Washington State Noxious Weed Control Board Web Site.