Distribution: British Columbia to California, east to Idaho
Habitat: Moist areas in the lowlands
Conservation Status: Not of concern
Rhizomatous annual, the stems dimorphic; sterile stems 5-30 dm. tall and 0.5-2 cm. thick, 20- to 40-ridged, the central cavity about 1/4 the diameter of the stem; stomates in 2 broad bands in the furrows; sheath 1-2.5 cm. long, with slender, tapered teeth 3-8 mm. long; fertile stems 2.5-6 dm. tall and 1.5-2 cm. thick; sheaths 2-5 cm. long, with 20-30 prominent teeth fused in groups of 2-4.
Branches only on sterile stems, whorled, ascending, 4- to 6-angled, solid, 1-2 mm. thick, sometimes again branched.
Cone 4-7 cm. long.