29. C. ripària, W. Curtis. Very large and stout, 2–4° high, stoloniferous; leaves mostly broad, flat, rough, glaucous, much longer than the sharply angled culm; spikes 2–4, scattered and all more or less peduncled, the lowest often very long-stalked, varying from almost globular in starved plants to 3–4´ long, erect or the lower somewhat drooping, loosely flowered below; perigynium ovate-lanceolate, coriaceous, rather lightly many-nerved, becoming polished, the beak short and thick; scale varying from blunt to awned, shorter or longer than the perigynium.—Swales; common. (Eu.)
C. acutifórmis, Ehrh. Stout, 2–3° high; culm thick and sharp, mostly smooth; leaves broad, flat and glaucous, much prolonged; spikes 3–5, all but the uppermost peduncled, spreading or drooping, narrowly cylindric (2–3´ long), loosely flowered below; perigynium ovate, very strongly many-nerved, the short beak slightly toothed; scale rough-awned and longer than the perigynium. (C. paludosa, Gooden.)—Swales, Dorchester, and New Bedford, Mass. (Nat. from Eu.) The former station has been recently destroyed.
[*] 3. Microrhynchæ.—[+] 1. Atràtæ.
[++] Alpine; plant small.
30. C. alpìna, Swartz. Small and slender, ½–2° high; culm thin and obtuse, smooth or roughish, naked above; leaves narrow and flat, shorter than the culm; spikes commonly 3, sometimes 2 or 4, aggregated, globular and very small, all closely sessile or rarely the lowest exceedingly short-stalked; perigynium orbicular or obovate, nerveless or nearly so, the short beak slightly notched, a little longer than the ovate and black mostly obtuse scale.—Isle Royale, L. Superior. (Eu.)
31. C. atràta, L., var. ovàta, Boott. Very slender but erect, 1–2° high; culm rather sharp, roughish above; leaves narrow but flat, shorter than the culm; spikes 3–5, all but the terminal one on slender stalks ½–2´ long, drooping when mature, 1´ long or less, ovate-oblong or short-cylindric, reddish-brown; perigynium broadly ovate, thin and puncticulate, very short-beaked, the orifice slightly notched; scale blunt, thin-margined, about as long as the perigynium. (C. atrata, Man.)—White Mountains, N. H., Smugglers' Notch, Vt. (Brainerd), and northward.
[++][++] Paludose; plant larger.
32. C. fúsca, All. Rather slender but stiff, 1–3° high; culm sharp, roughish above; leaves very narrow, rough, mostly shorter than the culm; spikes 2–4, the terminal rarely all staminate, all sessile and approximate or the lowest sometimes very short-stalked, varying from globular to narrowly cylindric (often becoming 1½´ long), dark brown or variegated; perigynium elliptic and beakless, whitish and granular, nearly nerveless, the orifice entire; staminate scales very long-lanceolate, the pistillate lance-ovate and very sharp, conspicuously longer than the perigynium. (C. Buxbaumii, Wahl.)—Bogs, throughout; frequent. (Eu.)
[*] 3.—[+] 2. Rígidæ.
33. C. vulgàris, Fries. Low and stiff, about 1° or sometimes 18´ high; culm sharp, smooth or rather rough above; leaves narrow and stiff, shorter than the culm, glaucous blue; staminate spike sessile or nearly so; spikes 2–4, all sessile or rarely the lowest very short-stalked, short and erect (1´ long or less), very densely flowered or sometimes becoming loose below, the lowest subtended by a bract 1–3´ long; perigynium appressed, oval or round-ovate, mostly finely striate toward the base, the beak entire or very nearly so, bright green until over-mature; scale ovate and very obtuse, purple with a faint white nerve, conspicuously narrower and shorter than the perigynium, thus causing the spike in the growing plant to assume a characteristic green-and-black appearance.—Swales and low meadows along the sea-board, from Mass. northward; common. (Eu.)