General:
Perennial, tufted herb from long, creeping rhizomes; stems triangular, with smooth edges, 15-120 cm tall, equalling the leaves.

Leaves:
Sheaths tight, short; blades flat, well distributed along the stem, 3-7 mm wide, the lower ones slightly reduced.

Flowers:
The terminal spikes 1 to 3, short-stalked, with male flowers, the lower spikes 2 to 7, with female flowers, unstalked or with short stalks, 3-14 cm long, erect; bracts subtending the spikes leaflike, sheathless, the lower ones longer than the inflorescence, the upper ones reduced.

Fruits:
Perigynia egg-shaped, 2-3.6 mm long, 1.3-2.3 mm wide, brownish-green, 3-angled, the angles rounded, smooth to somewhat wrinkled, 2-nerved, the beaks entire; female scales egg-shaped, shorter than or about as long as the perigynia, often shortly awn-tipped, brownish-red to blackish, with lighter 3-nerved centres, with translucent margins; stigmas 2; achenes lens-shaped, granular, 1.4-1.8 mm long. Two subspecies may be recognized in BC 1. Male spikes 2 to 3; plants generally more than 20 cm tall; plants more common southward ssp. aquatilis 1. Male spike 1; plants generally less than 20 cm tall; plants more common northward ssp. stans (Drej.) Hult.

Source:  The Illustrated Flora of British Columbia

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Illustration Source:  The Illustrated Flora of British Columbia

Synonyms and Alternate Names:
Carex acutinella Mack.
Carex aquatilis subsp. altior (Rydb.) HultΘn
Carex aquatilis subsp. aquatilis
Carex aquatilis var. altior (Rydb.) Fernald
Carex aquatilis var. substricta Kⁿk.
Carex substricta (Kⁿk.) Mack.
Carex suksdorfii Kⁿk.