[=][=] _Plant strict but not stiff._

113. C. cephaloidea, Dewey. Lax, very green, 2--3 high; leaves broad (2--3") and thin, shorter than the long culm; head rather loose, '

long or more, all but the very uppermost spikes clearly defined; perigynium ovate, entirely nerveless, long rough-pointed, spreading, twice longer than the very thin scale or more.--Shady banks, W. Ma.s.s. to Mich.; frequent.

114. C. cephalophora, Muhl. Mostly smaller and stricter, pale; leaves half as wide or less; head small, rarely ' long, globular or very short-oblong, never interrupted, the lower 1 or 2 spikes usually bearing a very setaceous short bract; perigynium twice smaller than in the last, scarcely longer than the rough-cuspidate scale.--Dry and mostly sterile knolls; common.

Var. angustiflia, Boott. Low, 8' high or less; leaves very narrow; head smaller, usually tawny; perigynium mostly broader.--West and southward; rare.

[*] 11.--[+] 6. _Diicae_.

[++] _Perigynium nerveless or very nearly so_.

115. C. capitata, L. Rigid, 3'--1 high; leaves filiform, shorter than the culm; head globular, uniformly staminate above, brown, very small; perigynium broadly ovate, very thin, whitish, prominently beaked, erect and appressed, longer than the very thin and obtuse scale.--Alpine summits of the White Mountains. (Eu.)

[++][++] _Perigynium prominently nerved_.

116. C. gyncrates, Wormsk. Stiff but very slender, 3--6' high, dicious; leaves filiform and setaceous, about the length of the culm; spike oblong, 2--4" long; perigynium elliptic-ovate, nearly terete, stipitate, widely spreading or reflexed at maturity, 1 or 2 sometimes borne at the base of the staminate spike.--Cold sphagnum swamps, Penn., north and westward; local, particularly southward.

117. C. exlis, Dewey. Very stiff, slender, 1--2 high; leaves involute-filiform and very stiff, shorter than the culm; spike varying from almost globular to cylindrical (frequently 1' long), either unis.e.xual or the s.e.xes variously placed, very rarely a supplementary spike at base; perigynium elliptic-ovate, flattish, stipitate and somewhat cordate at base, strongly brown-nerved on the outer face, rather faintly nerved on the inner, rough-edged above, sharply toothed, spreading, a little longer than the scale.--Cold swamps and lake-borders, N. Eng. and eastern N. Y. to N. J.; rare.

[*] 12. HYPARRHeNae.--[+] 1. _Elongatae_.

[++] _Perigynium very sharp-margined, firm, often thickened at base, spreading in open and at maturity stellate spikes._

118. C. echinata, Murray, var. cephalantha, Bailey. Rather stiff but slender, 1--2 high; leaves very narrow and involute, about the length of the culm; spikes 5--8, approximate or even aggregated into a head, green, compactly 15--30-flowered, short-oblong or nearly globular; perigynium ovate-lanceolate, rough on the margins above, nerved on both faces, spreading or reflexed at maturity, the beak long and prominent, longer than the sharp white scale. (C. stellulata, last ed.)--E. Penn.

(_Porter_) to Ma.s.s. (_Morong_), and westward to L. Superior; rare.--Var.

CONFeRTA, Bailey. Very stiff; spikes contiguous or scattered, spreading, short-oblong or globular, dense; perigynium broadly ovate or even nearly round-ovate, very strongly nerved, reflexed or widely spreading. Near the sea-coast; uncommon. The perigynia resemble those of n. 112.--Var.

MICRoSTACHYS, Boeckl. Mostly very slender; spikes few, 3--10-flowered, usually tawny; perigynium small, lance-ovate, nerved on the outer face but usually nerveless on the inner, erect or spreading, the beak rather long or prominent. (C. scirpoides, _Schkuhr._ C. sterilis, _Willd._) Swales, throughout; very common and variable.--Var. ANGUSTaTA, Bailey.

Exceedingly slender; spikes few and very few-flowered, mostly all contiguous; perigynium lanceolate or linear-lanceolate, twice the length of the scale or more. N. Y., Vt., and northward; rare.

[++][++] _Perigynium scarcely sharp-margined, thin in texture, not thickened at base, mostly in closely flowered and rounded or oblong spikes._

[=] _Perigynium ovate or nearly so, the beak short or none._

[a.] _Bracts not prolonged._

119. C. canescens, L. Stiff and rather stout, 1--2 high, glaucous and pale throughout, growing in stools; spikes 4--8, globular or oblong, very densely 20--50-flowered, approximate or somewhat scattered on the upper part of the culm, usually prominently contracted below with the staminate flowers; perigynium short-ovate, silvery-white and minutely puncticulate, never thickened at base, faintly few-nerved, smooth throughout, ascending, the beak very short and entire; scale obtuse or acutish, about the length of the perigynium.--Cool swamps and bogs, N.

Eng. to Penn., west and northward; frequent northward. (Eu.)

Var. vulgaris, Bailey. Very slender, lower, not glaucous, in small and loose tufts; spikes smaller and usually fewer, loosely flowered; perigynium mostly more beaked, prominently spreading.--Mostly in drier places; very common. Perigynium much shorter than in any form of n. 118.

Var. alpicola, Wahl. Low and stiff, or at lower alt.i.tudes becoming somewhat slender, seldom much over 1 in height; spikes small, globular or nearly so, dense, well defined and brown or tawny; perigynium as in the type, ascending. (C. vitilis, _Fries._)--Mountains from N. Eng. to Ga., sparingly along our northern boundary, and far westward. (Eu.)

Var. polystachya, Boott. Erect and mostly strict, not glaucous, 1--2 high, scarcely tufted; leaves very lax and exceeding the culm; spikes oblong, more or less aggregated in an oblong interrupted head, the lowest 1 or 2 subtended by short scale-like bracts; perigynium somewhat spreading. (C. arcta, _Boott_.) Low woods, N. New Eng. to N. Minn.; rare. Resembles C. echinata, var. cephalantha.

120. C. Norvegica, Willd. Low and stiff, but rather slender, 1 high or less; leaves very narrow, mostly shorter than the culm; spikes 3--5, somewhat scattered, brown, globular or oblong, compactly many-flowered, the terminal one long-contracted below with the staminate flowers; perigynium very short-ovate, thick, the beak rough, a little longer than the very obtuse scale.--Salt marshes, Maine, and northward, rare. (Eu.)

121. C. tenuiflra, Wahl. Very slender and diffuse, 1--1 high, in tufts; leaves very narrow and lax, shorter than the filiform culm; spikes 2--4, all loosely few-flowered and silvery-green, and aggregated into a small globular head; perigynium elliptic, obscurely nerved, smooth, beakless, spreading, about the length of the white thin scale.--Bogs, N. New Eng. to N. Minn.; local. (Eu.)

[b.] _Bracts much prolonged, the lowest 2--3' long._

122. C. trisperma, Dewey. (Pl. 6, fig. 1--5.) Exceedingly slender, in small and loose tufts, the weak reclining culms 1--2 long; leaves soft and narrow, shorter than the culm; spikes 2--3, 1--3' apart, silvery-green, 2--3-flowered; perigynium very thin, finely nerved, the beak entire or nearly so; scale acute, very thin, usually shorter than the perigynium.--Cold bogs, throughout; common northward.

[=][=] _Perigynium ovate-lanceolate to linear-lanceolate._

123. C. Deweyana, Schwein. Weak, 1--1 high; leaves flat and soft, shorter than the culm, yellowish-green; spikes 3--6, mostly oblong or sometimes but 2--3-flowered, loose, the upper ones contiguous but the lower 1 or 2 usually considerably separated on the zigzag rhachis and mostly subtended by a bract, all silvery-green; perigynium ovate-lanceolate or narrower, very thin in texture, nerveless, somewhat thickened below on the outer face, the long beak rough; scale very thin, acute or cuspidate, about the length of the perigynium.--Dry woods; common.

124. C. bromodes, Schkuhr. Lax, 1--2 high, in dense stools; leaves very narrow, about as long as the culm; staminate flowers variously situated in the head, sometimes a few spikes wholly sterile, rarely the plants dicious; spikes 3--6, oblong or short-cylindric, erect, silvery-tawny or brown; perigynium linear-lanceolate, firm especially at the base, prominently nerved, the long and roughened beak toothed; scale sharp, shorter than the perigynium.--Open bogs; common.

[*] 12.--[+] 2. _Ovales._

[++] _Perigynium ovate-lanceolate, with winged margins._

125. C. siccata, Dewey. Extensively creeping, 1--2 high, erect; leaves firm, narrow, about the length of the culm; staminate flowers variously situated, usually some of the spikes wholly sterile; spikes 3--5, aggregated or separated, ovoid or short-oblong, silvery-brown; perigynium firm, nerved on both faces, the long beak rough and toothed, the margins prominent or sometimes very narrow; scale acute, about the length of the perigynium.--Sandy fields and banks, N. Eng. to Ohio, west and northward; frequent.

[++][++] _Perigynium ovate-lanceolate or narrower, scale-like, with little distinction between body and margin._

126. C. Muskingumensis, Schwein. Robust, erect, 2--3 high; leaves many and lax, loosely sheathing, those on the sterile shoots crowded near the top, all flat and long-pointed; spikes 6--12, contiguous, erect, narrowly cylindric (often 1' long), becoming light brown and presenting a dried appearance, very densely flowered; perigynium linear-lanceolate (3" long), prominently nerved, ciliate on the white margins above, appressed, twice the length of the scale or more. (C. arida, _Schwein. & Torr._)--Woods and copses, Mich. and Ohio to Ill. and Wisc.; local.

127. C. tribulodes, Wahl. Stout and erect, 2--3 high; leaves narrower than in the last, loosely sheathing; spikes 6--15, aggregated into an oblong or somewhat interrupted heavy head, short-oblong or sometimes nearly globular, green or tawny-green, compact, not narrowed above; perigynium linear-lanceolate (3" long), obscurely nerved, erect but the points conspicuous, rough-margined, nearly twice the length of the scale. (C. lagopodioides, _Schkuhr_.)--Open swales; frequent.--Var.

TURBaTA, Bailey. Culm softer and often lax; the leaves broader; spikes more loosely disposed, forming a head 1--2' long, which is slender and more or less interrupted but always erect, green, becoming tawny, if at all, only when the perigynia begin to fall, obovate-oblong ( to rarely ' long), contracted below; perigynium ascending and more appressed, the points therefore not conspicuous. Woods, throughout; rare.--Var.

REDuCTA, Bailey. Very slender, 1--2 high, the culm projecting beyond the leaves; spikes 2--10, small and nearly globular (usually less than 3" broad), all usually distinct, the lowest separated, brown, especially at maturity, the head often flexuose; perigynium small, the points spreading and conspicuous. Copses, N. Eng. to Dak.; infrequent.

Var. Bebbii, Bailey. Stiff or rather slender, erect, 1--2 high; head dense, ovoid or oblong (--' or very seldom 1' long), the lowest spike only rarely distinct, straw-colored; spikes small (3" long or less), their axes ascending; bracts at the base of the head small or none; points of the small perigynium conspicuous. (C. Bebbii, _Olney_.)--Dry low grounds, throughout; common.

Var. cristata, Bailey. Stout and stiff, 1--3 high; head more or less open or at least the lower 1 or 2 spikes commonly distinct, 1' long or more, green; spikes larger than in the last and almost exactly globular, their axes more divergent or fully horizontal; bracts usually conspicuous, sometimes one of them foliaceous; perigynium spreading, the points more conspicuous. (C. cristata, _Schwein_.)--Moist ground, throughout from Penn. northward; common.

128. C. scoparia, Schkuhr. Rather slender but erect, 1--2 high; leaves very narrow, shorter than the culm; head short and comparatively thick, always tawny or brown, bractless or nearly so; spikes 3--8, all contiguous or bunched, ovate-oblong, always prominently narrowed or cone-shaped above, ascending; perigynium as in n. 127, but erect or ascending.--Open swales, throughout; common eastward.

Var. mnor, Boott. Much smaller, 6--10' high, the leaves very narrow; head very small and darker brown; spikes very small (2--4"

long).--Rocky and sterile places, northward; frequent.

[++][++][++] _Perigynium ovate or broader, thickened in the middle, wing-margined (in n. 129 marginless)._

[=] _Head silvery-brown, silvery-green, or silvery-whitish._

129. C. adusta, Boott. Very stiff and stout, 1--2 high, in dense tufts; head very heavy, erect, varying from globular to oblong, silvery-brown; spikes 5--10, globular and heavy, all aggregated or sometimes distinct, the lowest 1 or 2 subtended by a short and very broad-based, nerved and pointed bract; perigynium broadly ovate, wingless or very nearly so, plump, shining, nerved on the outer face but nerveless on the inner, filled by the large achene; scale acute, about the length of the perigynium. (C. pinguis, _Bailey_.)--Dry and mostly hard soils, Mt. Desert, Maine (_Greenleaf_), and northward, and Crawford Co., Mich. (_Bailey_), to N. Minn., and far northwestward; local.

130. C. f'nea, Willd. Slender, erect or the top of the culm flexuose, 1--2 high; head long and weak, often nodding; spikes 5--8, small, nearly globular and much contracted below, silvery-green, alternately disposed; perigynium varying from ovate to long-ovate, very thin, much longer than the small achene, prominently rough-margined, strongly many-nerved on both faces, especially on the small inner face; bracts entirely wanting or inconspicuous. (C. adusta, last ed.)--Dryish copses, N. Eng. to Penn. and Minn.; not common.--Var. PERPLeXA, Bailey.

Mostly taller and stouter; spikes larger and less attenuated or even truncate below, approximate or even aggregated, the head erect or nearly so and the lowest bract occasionally prominent; perigynium thicker and firmer in texture. N. Eng. to Minn.; infrequent.

131. C. silicea, Olney. Stiff, 1--2 high, in clumps; leaves very narrow, becoming involute, not exceeding the culm; head 1--3' long, usually flexuose or nodding above the middle at maturity; spikes 5--8, silvery-white or silvery-tawny at full maturity, all more or less separated, ovate, conspicuously contracted below and cone-shaped above, erect on the culm; perigynium very broad-ovate and very thin, obscurely nerved, appressed, about as long as the acute colorless scale. (C.

fnea, var. sabulonum, last ed.; C. straminea, var. moniliformis, _Tuckerm_.)--Sands of the sea-sh.o.r.e, Maine to N. J.; frequent.

[=][=] _Head dull brown or green (usually somewhat silvery in_ var.

fnea _of n. 132)._

132. C. straminea, Willd. Very slender, erect, but the top of the culm often flexuose, 1--3 high; leaves narrow and long-pointed, stiff, shorter than the culm; spikes 3--8, tawny, very small (2--3" broad), globular or sometimes a little tapering below from the presence of many staminate flowers, usually all entirely distinct on the very slender, often zigzag or flexuose rhachis; bracts none, or only the lowest conspicuous; perigynium small and ovate, nerved on both faces but never unusually prominently nerved on the inner face (as is the perigynium of n. 130), the points spreading and rather conspicuous; scale acute, about the length of the perigynium. (C. straminea, var. tenera, last ed.)--Dryish copses and fields; common. Immensely variable.