Var. strictifórmis, Bailey. Taller (1½–2½° high) and looser; culms slender; leaves long and narrow, lax, scarcely glaucous; staminate spike longer peduncled; pistillate spikes looser and often longer, mostly brown or tawny-green. (C. limula, Man.)—Swales from E. Penn. northward, near the seaboard; frequent. Often confounded with n. 34, but easily distinguished by the non-cespitose habit, sheaths not fibrillose, and the short scales very obtuse.
Var. hyperbòrea, Boott. Somewhat stoloniferous, low, often smaller than the type; spikes shorter and mostly loosely flowered, often becoming very thin; scales generally longer, giving the spikes a darker color; stigmas often 3. (C. rigida, var. (?) Bigelovii, Tuckerm.)—Alpine summits of N. H., Vt., and N. Y. (Eu.)
[*] 3.—[+] 3. Acùtæ.
[++] Stigmas 2; scales not conspicuously acute, or if so, divaricate.
[=] Spikes erect, or rarely spreading in n. 34.
34. C. strícta, Lam. Tall and slender but erect, 2–4° high, generally in dense clumps when old, or rarely in small tufts; culm sharp, rough above; leaves long and narrow, rough on the edges, the lowest sheaths usually becoming prominently fibrillose; 1 or 2 lowest bracts leafy and equalling the culm; spikes 3–5, variable in size and shape, scattered, the lowest usually more or less peduncled and clavate and the others sessile, erect or spreading, oblong or cylindric (½–2´ long and 2–3´´ broad), all compactly flowered above but often attenuate at base (or rarely alternate-flowered throughout), the upper mostly staminate at top, all greenish-purple or pallid; perigynium ovate and small, tawny, mostly lightly few-nerved and somewhat granular, the beak very short and commonly entire; scale obtuse to nearly acute, about equalling the perigynium or a little shorter.—Swales, throughout; abundant and variable.
Var. angustàta. Stricter; spikes longer and narrower (3–4´ long about 1½´´ broad), never clavate, more approximate and always erect, the staminate portion usually much longer (often 1–2´), rust-colored; scales narrower and sharper, mostly longer than the perigynium. (C. angustata, Boott, in part.)—Same range as the type, but less common.
Var. decòra, Bailey. Usually smaller; basal sheaths rarely fibrillose; spikes shorter (seldom over 1´ long), sessile or very nearly so, rarely attenuate at base, spreading, the terminal staminate flowers few, rust-colored; bracts more spreading; scales very sharp and spreading, longer than the perigynium. (C. aperta, Man.)—N. Eng. to Wisc.; rather rare.
C. strícta × filifórmis. Leaves and culms very slender; spikes short (1´ long or less), sessile and compact, the upper 1 or 2 scarcely bracted, pallid; perigynium small, smooth.—Keweenaw Co., Mich. (Farwell.) Exactly intermediate between the two species.
35. C. aquátilis, Wahl. Large and stout, glaucous, 2–4° high; culm very obtuse and smooth; leaves exceedingly long, broader than in the last, the bracts broad and prolonged far beyond the culm; spikes 3–5, 1–2´ long, very compact or the lowest sometimes attenuate below, erect, thick (3´´ broad or less); perigynium round-ovate or broadly elliptic, nerveless, greenish, imbricated; scale obtuse and much shorter and narrower than the perigynium.—Swamps and lake-margins, N. Eng. to Minn.; not common. (Eu.)