[++][++] Perigynium large, prominently inflated.

56. C. formòsa, Dewey. Slender, erect, 1–2½° high; leaves flat, mostly rather broad, those of the culm very short; spikes 3–5, scattered, oblong or short-cylindrical (1´ long or less), compact, all flexuose or drooping; perigynium ovate, puncticulate, obscurely nerved, short-beaked with a slightly notched orifice, all but the lowest one or two twice longer than the blunt or cuspidate scale.—Woods and copses, Vt. to Mich.; local.

57. C. Davísii, Schwein. & Torr. Always taller; spikes heavier; perigynium more inflated, strongly nerved and prominently toothed, no longer or shorter than the conspicuously awned and spreading scale.—Wet meadows, W. Mass. to S. Minn., and southward; rare east and northward.

[*] 4.—[+] 6. Gríseæ.

58. C. grísea, Wahl. Stout, 1–2° high; leaves broad (2–3´´) and slightly glaucous; bracts broad and leaf-like, diverging, very much exceeding the culm; staminate spike small and sessile; pistillate spikes 3–4, short (1´ long or less), the highest two usually contiguous to the staminate spike and sessile, the others somewhat remote and peduncled, all erect, compact; perigynium oblong, pointless, marked with impressed nerves, turgid and cylindric, all but the lowest longer than the narrow, cuspidate or blunt, nerved scale.—Moist grounds, throughout, except along our northern borders; common.—Var. angustifòlia, Boott. Much more slender; leaves scarcely half so wide, the bracts, especially, much narrower and shorter and more erect; spikes slender, perigynium scarcely inflated, triangular-oblong, bearing a sharp beak-like point, 2-ranked; scale nerveless, long-awned and spreading. N. J. to S. Ohio, and southward; common.—Var. globòsa, Bailey. Low, 3–12´ high, often spreading; spikes few-flowered, often with but 2 or 3 perigynia; perigynium short, inflated, very blunt, nearly globose or obovate; scale short, not prominently cuspidate or the upper ones wholly blunt. Mo., Kan., and southward.

Var. (?) rígida, Bailey. Rigid; leaves rather narrow, long and erect; staminate spike prominently peduncled; pistillate spikes scattered, all more or less stalked, conspicuously 2 ranked; perigynium triangular-oblong, hard, longer than the cuspidate ascending scale.—Sellersville, Penn., and Del.

59. C. glaucodèa, Tuckerm. Lax or somewhat strict (6–18´ high), densely glaucous; leaves flat, variable in width; spikes as in n. 58; perigynium firm, not inflated, prominently impressed-nerved, glaucous, longer than the short-cuspidate or blunt thin and appressed scale. (C. flaccosperma, last ed.)—Meadows and swamps, Mass. to S. Ill., and southward; local.

[*] 5. Spirostàchyæ.—[+] 1. Granulàres.

61. C. Cràwei, Dewey. Low, strict, stoloniferous (4–12´ high); leaves narrow; bracts scarcely exceeding the culm; spikes 2–4, scattered, the lowest radical or nearly so, short-peduncled or the upper sessile, erect, compact, 9´´ long or less; staminate spike generally peduncled; perigynium ovate, usually resinous dotted, obscurely or few-nerved, very short-pointed, longer than the obtuse or short-pointed scale.—Moist places, N. Y. to Ill. and Minn.; local, especially eastward.

[*] 5.—[+] 2. Exténsæ.

C. exténsa, Gooden. Slender but strict, 1–2° high; leaves involute; spikes about 3, the lowest remote and short-peduncled, the remainder approximate and sessile, short (about ½´ long) and compact; perigynium ovate, very strongly nerved, ascending, the short stout beak sharply toothed, longer than the blunt brown-edged scale.—Long Island and Coney Island, N. Y.; Norfolk, Va., McMinn. (Nat. from Eu.)

62. C. flàva, L. Very slender but strict and stiff, 1–2° high, yellowish throughout; leaves flat but narrow, mostly shorter than the culm; staminate spike sessile or nearly so, usually oblique; pistillate spikes 2–4, all contiguous or rarely the lowest one remote, all but the lowest sessile, short-oblong or globular, densely flowered, the lowest subtended by a long divaricate bract; perigynium ovate, produced into a deflexed beak as long as the body, strongly nerved, thrice longer than the blunt scale.—Swales and wet meadows, N. Eng. to L. Superior; rare westward. (Eu.)—Var. gráminis, Bailey. Smaller and green, 6–12´ high; leaves mostly longer than the culm; bracts erect; perigynium straight or nearly so, the beak often rough. Grassy places, probably common and generally distributed.

Var. virídula, Bailey. Small and slender, very strict, green or greenish-white; leaves narrow, equalling or exceeding the culm; bracts long and strictly erect, spikes very small or sometimes becoming cylindric, more closely aggregated; perigynium conspicuously smaller, the beak very short and straight. (C. Œderi, last ed.)—Cold bogs, N. Eng. to Penn., and northwestward; local.

[*] 5.—[+] 3. Pallescéntes.

[++] Perigynium wholly beakless.

63. C. palléscens, L. Slender, erect, 4´–2° high, tufted; leaves narrow, flat, the lower slightly pubescent, particularly on the sheaths; spikes 2–4, ½´ long or less, densely flowered, all but the upper one very shortly peduncled, erect or spreading; perigynium globular-oblong, thin and very nearly nerveless, about the length of the cuspidate scale.—Glades and meadows, N. Eng. to Penn., Wisc. and L. Superior; rare westward. (Eu.)

[++][++] Perigynium very stout-beaked.

[*] 6. Dactylostàchyæ.—[+] 1. Oligocárpæ.

[++] Sheaths smooth.

65. C. conoídea, Schkuhr. Slender but strict, 1–1½° high; staminate spike long-peduncled or rarely nearly sessile; spikes 2–3, scattered, short-stalked or the upper one sessile (the lowest frequently very long-stalked), oblong (rarely 1´ long) and rather loosely flowered, erect; perigynium oblong-conical, impressed-nerved, gradually narrowed to a point, the orifice entire; scale loosely spreading and rough-awned, equalling or exceeding the perigynium.—Moist grassy places, N. Eng. to Ill., and southward; rare westward.

66. C. oligocárpa, Schkuhr. Diffuse, 10–18´ high; bracts flat and spreading; staminate spike sessile or stalked; spikes 2–4, scattered, stalked or the uppermost sessile, loosely 2–8-flowered, erect; perigynium small, hard, finely impressed-nerved, abruptly contracted into a conspicuous mostly oblique beak, the orifice entire; scale very loosely spreading and rough-awned, longer than the perigynium.—Dry woods and copses, W. New Eng. to Mo., and southward; rare westward. Often confounded with small forms of n. 58.

[++][++] Sheaths pubescent.

67. C. Hitchcockiàna, Dewey. Erect, 1½–2° high; spikes 2–4, all more or less peduncled, very loosely few-flowered, erect; perigynium triangular-ovate, many-striate, the strong beak prominently oblique, shorter than the rough-awned scale.—Rich woods, W. New Eng. to Ill., and southward to Penn. and Ky.; frequent.

[*] 6.—[+] 2. Laxiflòræ.

[++] Sheaths green.

[=] Perigynium mostly obscurely triangular, the beak very prominent.

[=][=] Perigynium sharply triangular, short, and mostly not prominently beaked.

a. Spikes drooping or flexuose.

69. C. digitàlis, Willd. Very slender, bright green, tufted, 6–18´ high; leaves very narrow (1–2´´ wide); staminate spike short stalked; pistillate spikes 2–4, all on filiform stalks and all but the upper widely spreading or drooping, linear, alternately flowered; perigynium very small, impressed-nerved, longer than the acute whitish scale.—Dryish woods and glades, N. Eng. to Mich., and southward; frequent.—Var. copulàta, Bailey. Leaves much broader, and the culms weak and reclined; spikes heavier and mostly shorter; perigynium larger, very sharp. Rich woods, central Mich., and probably elsewhere westward.

70. C. laxicúlmis, Schwein. Differs from the variety of n. 69 chiefly in its more cespitose habit, its densely glaucous-blue covering, very slender culm, and very long and filiform peduncles. (C. retrocurva, Dewey.)—Glades, N. Eng. to Mich. and Va.; rare westward.

b. Spikes erect.

71. C. ptychocárpa, Steudel. Low, glaucous, 3–10´ high; leaves flat and rather broad (2´´ or more), much exceeding the culm; bracts leafy and much prolonged; staminate spike very small and sessile, mostly overtopped by the upper pistillate spike; pistillate spikes 2–3, sessile or short-stalked or rarely the lowest long-peduncled, erect; perigynium tawny, much as in n. 69, twice longer than the very thin obtuse scale.—Low grounds or swamps, E. Mass., N. J., Del., and southward; local.

72. C. platyphýlla, Carey. Low, spreading, glaucous, 6–12´ high; leaves ½´ broad or more, mostly shorter than the culms; bracts with thin and sharp-pointed leaf-like tips 1–2´ long; staminate spike stalked; pistillate spikes 2–3, scattered, all more or less peduncled, alternately 2–10-flowered; perigynium short, strongly many-striate, about the length of the acute or cuspidate scale.—Rich shady woods and banks, N. Eng. to Mich., and southward to Va.; mostly local.

[++][++] Sheaths usually purple.

74. C. plantagínea, Lam. Slender but erect, 1–2° high; leaves ½–1´ broad, very firm, appearing after the flowers and persisting over winter, shorter than the culm; staminate spike purple and clavate, stalked; pistillate spikes 3–4, scattered, loosely few-flowered, erect, the peduncles included in the leafless sheaths; perigynium smaller than in n. 73, prominently beaked, about as long as the sharp scale.—Rich woods, N. Eng. to Wisc., and southward; local.

[*] 6.—[+] 3. Paníceæ.

[++] Beak cylindrical and prominent; plant not glaucous.

75. C. Saltuénsis, Bailey. Very slender and more or less diffuse, strongly stoloniferous, 1–1½° high; leaves narrow and soft, shorter than the culm; spikes 2–3, scattered, all peduncled and more or less spreading, loosely 3–10-flowered; perigynium small, nearly nerveless, thin, the beak straight and sharply toothed; scale loose, acute, shorter than the perigynium. (C. vaginata, last ed.)—Deep swamps, Vt. to Minn.; local.

76. C. polymórpha, Muhl. Stout, 1–2° high; leaves rather broad, short; spikes 1–2, short-stalked, erect, compact or rarely loose, usually staminate at the apex, 1½´ long or less; perigynium long-ovate, obscurely nerved; the very long and nearly straight beak oblique or lipped at the orifice; scale reddish-brown, obtuse, shorter than the perigynium.—Moist meadows, Mass. to N. C.; local.

[++][++] Beak short or none; plant often glaucous.

[=] Plants of ordinary habit.

77. C. tetánica, Schkuhr. Rather slender, rarely glaucous, somewhat stoloniferous; culm scabrous, at least above; spikes all peduncled, the upper one very shortly so, pale, all more or less attenuate below, the lower borne in the axils of bracts 3´ long or more; perigynium not turgid, greenish, prominently many-nerved, the beak strongly bent; scale obtuse or abruptly mucronate, all except the lowest mostly shorter than the perigynium.—Meadows and borders of ponds from W. Mass. westward; common westward.—Var. Woòdii, Bailey. Very slender and strongly stoloniferous; leaves narrow, very long and lax; spikes mostly alternately flowered throughout; scales often sharper. (C. Woodii, Dewey.) Rich woods, N. Y. to Mich., and south to Washington; frequent.—Var. Mèadii, Bailey. Stiffer; leaves mostly broader and stricter; spikes thick and densely flowered, not attenuate at base, the upper one often sessile; perigynium larger. (C. Meadii, Dewey.) R. I. to Neb., and southward; rare eastward.—Var. Cánbyi, Porter. Stout and stiff; leaves still broader (about 2´´ wide) and flat; spikes thick, often ¼´ wide; perigynium long, straight or very nearly so; scale large, nearly equalling or exceeding the perigynium. E. Penn. (Canby); Ill. and Wisc.; little known.

C. panícea, L. Strict, often stiff, glaucous-blue 1–2° high; culm smooth; bracts 1–2´ long; spikes 1–3, scattered, colored, peduncled, erect, rather compact or loose below, seldom 1´ long; perigynium ovoid, yellow or purple, somewhat turgid, scarcely nerved, the point usually curved, mostly longer than the purple-margined scale.—Fields, E. Mass. and R. I. (Nat. from Eu.)

78. C. lívida, Willd. Culms 18´ high or less; leaves narrow, often becoming involute; spikes 1 or 2 and aggregated or approximate, or rarely a third nearly radical, sessile or nearly so, erect, narrow; perigynium ovoid-oblong, nerved, granular, beakless, the point straight or nearly so, orifice entire; scale obtuse, mostly a little shorter than the perigynium.—Pine-barrens of N. J., and sphagnum swamps northward to N. Eng. and L. Superior; local. (Eu.)

[*] 6.—[+] 4. Bicolòres.

79. C. aùrea, Nutt. Low and slender, 1° high or less; bracts exceeding the culm; spikes 2–4, all but the lowest usually approximate, peduncled or the upper one or two sessile, erect, loosely few-flowered or sometimes becoming ¾´ long, at maturity yellow or brown, the terminal one frequently pistillate above; perigynium fleshy at maturity, nerved, longer than the blunt scale.—Wet meadows and springy banks, throughout; rather common.

[*] 6.—[+] 5. Digitàtæ.

[++] Spikes two or more.

80. C. ebúrnea, Boott. Exceedingly slender and capillary, erect, 4–12´ high, stoloniferous; leaves shorter than the culm; staminate spike very small and very short-peduncled, overtopped by the two upper pistillate spikes; pistillate spikes 2–4, approximate or the lowest remote, all stalked, erect, 2–6-flowered; perigynium very small, almost nerveless, smooth and becoming black and shining at full maturity; scale white and thin, obtuse, shorter than the perigynium.—Tufted in sandy or light soils from N. Eng. to Ky. and Neb.; frequent.

81. C. Richardsòni, R. Br. Rather stiff, 4–9´ high, stoloniferous; sheaths short, purple or brown; staminate spike stout and mostly short-peduncled; pistillate spikes 1–2, approximate, the very short stalks included, erect, compact, less than ½´ in length; perigynium obovoid, firm, hairy, the very short beak entire or erose; scale brown with a conspicuous white-hyaline margin, obtuse or pointless, and longer than the perigynium.—Dry ground, western N. Y. to Ill., and northwestward; rare.

82. C. pedunculàta, Muhl. Low and diffuse, 3–10´ high, forming mats; leaves abundant, very green, flat and firm, longer than the weak culms; staminate spike very small, with the uppermost pistillate spike sessile at its base; pistillate spikes 2–4 on each culm, scattered and long-peduncled from green sheaths, erect or spreading, many other spikes nearly or quite radical and very long-stalked, all 3–8-flowered; perigynium triangular-obovate, smooth or very slightly pubescent above, the short and nearly entire beak somewhat oblique; scale green or purple, truncate and cuspidate, mostly a little longer than the perigynium.—Dry woods and banks, N. Eng. to Va. (Kennedy) and Minn.; frequent northward.

[++][++] Spike one or rarely a rudiment of a second; plant diœcious.

[*] 7. Sphæridióphoræ.—[+] 1. Scirpìnæ.

84. C. scirpoídea, Michx. Strict, the pistillate plant mostly stiff, 6–18´ high; leaves flat, shorter than the culm; spike 1´ long or less, densely cylindrical, very rarely with a rudimentary second spike at its base; perigynium ovate, short-pointed, very hairy, about the length of the ciliate purple scale.—Mountains of N. New Eng.; Drummond's Island, L. Huron. (Norway.)

[*] 7.—[+] 2. Montànæ.

[++] Some or all of the culms longer than the leaves (or in the type of n. 85 frequently shorter).

[=] Staminate spike minute, wholly or partially concealed in the head; leaves always very narrow; radical spikes often present.

85. C. defléxa, Hornem. Diffuse and low, tufted; culms 1–6´ high, setaceous, more or less curved or spreading, little exceeding or shorter than the leaves; staminate spike exceedingly minute and nearly always entirely invisible in the head; pistillate spikes 2–3, 2–5-flowered, green, or green and brown, all aggregated into a head, the lowest one always more or less short-peduncled and subtended by a leafy bract ½´ long or less; radical spikes few; perigynium very small and much contracted below, sparsely hairy or nearly smooth, the beak flat and very short, mostly longer than the acutish scale. (C. Novæ-Angliæ, last ed., mostly.)—High mountains of N. H. and Vt.

Var. Dèanei, Bailey. Taller and lax, the culms 6–12´ high and some or all prominently longer than the longer and loose leaves; staminate spike much larger (2–3´´ long), erect or oblique, sessile; pistillate spikes larger (4–8-flowered), less aggregated or the lowest usually separated, though rarely more than ¼´ apart; radical spikes usually numerous; bract mostly longer.—Swales or dryish places, high or subalpine regions, Mt. Desert, Maine (Rand); Essex, Mass.; N. H., Vt., and N. Y.; scarce. In aspect like n. 86.

Var. mèdia, Bailey. Rather stiff, 4–12´ high, in dense tufts; most of the spikes equalling or exceeding the leaves, the staminate prominent, erect (3–5´´ long), sessile or very short-peduncled; pistillate spikes 2–3, all scattered, the uppermost at or near the base of the staminate spike, the lowest usually very prominently peduncled and subtended by a conspicuous bract which surpasses the culm, all rather compactly 3–8-flowered, green, or brown and green; radical spikes several; perigynium larger, much like that of short-beaked forms of n. 90.—Keweenaw Co., Mich. (Farwell); also far westward.

86. C. vària, Muhl. Erect, mostly strict, 6–15´ high, tufted and somewhat stoloniferous; culms variable in length, often twice longer than the leaves; staminate spike 3´´ long or less; pistillate spikes closely aggregated, or rarely somewhat loosely disposed but never scattered, all strictly sessile, green; radical spikes none; lower bract usually present; perigynium longer-pointed than in the last, about the length of the sharp scale. (C. Emmonsii, Dewey.)—Banks and dry woods; frequent.—In var. coloràta, Bailey, the scales are purple. Mostly southward.

a. Scales smooth.

87. C. Nòvæ-Ángliæ, Schwein. Very slender and soft, erect, stoloniferous, 6–8´ high; culms little longer than the very narrow leaves; staminate spike exceedingly narrow (3–8´´ long by about ½´´ wide), mostly minutely peduncled; pistillate spikes 2, or rarely 3, the upper one near the base of the staminate spike, the lower very short-peduncled and removed ½–1´ and subtended by a leafy bract which nearly or quite equals the culm, both rather loosely 3–6-flowered; perigynium very narrow, often nearly oblanceolate, small, very thinly hairy, the beak sharp and prominent; stigmas often 2.—Mountain swamps of W. Mass., and Mt. Desert, Maine (Rand); rare.

88. C. Pennsylvánica, Lam. A foot high or less, erect, strongly stoloniferous, forming large patches; leaves narrow and more or less involute, dark or dull green, mostly nearly as long as the culm; staminate spike ½´ (rarely ¾´) long, usually dull brown or brown-purple, sessile or very nearly so; pistillate spikes 1–3, contiguous or the two lower rarely ½´ apart, all sessile and usually dark-colored, the lowest bract very short or at least rarely prominent; perigynium short- or round-ovate, hairy.—Dry fields; our commonest species.

89. C. commùnis, Bailey. Habitually taller and stricter, 8–18´ high, in small tufts, never stoloniferous; leaves proportionately shorter, broad (about 2´´), flat and pale; staminate spike mostly longer, often short-peduncled and usually paler; pistillate spikes 2–4, scattered on the upper part of the culm, green or tawny, the lowest one or two sometimes peduncled and often with prominent leafy bracts. (C. varia, last ed.)—Dry hill-sides; common.

Var. Wheèleri, Bailey. Mostly greener, 3–14´ high; leaves soft and flat and much shorter than the culm; staminate spike ¼´ long or less, very narrow, sessile and oblique; pistillate spikes mostly closer together.—Knolls in woods, Ionia Co., Mich. (Wheeler), and Alcona Co. (Bailey); Middletown, Conn. (Barratt), and Cheshire Co., N. H. It has much the aspect of n. 86, but is readily distinguished by the broad leaves and more scattered spikes.

b. Scales rough-cuspidate.

C. præ̀cox, Jacq. Rather stiff, the culm sometimes curved, 3–10´ high; leaves flat, shorter than the culm; staminate spike prominently clavate, mostly sessile; pistillate spikes 2–3, all contiguous, sessile or the lowest very short-peduncled and subtended by a bract scarcely as long as itself, all oblong or short-cylindric, the lowest about 6´´ long; perigynium triangular-obovoid, the very short beak entire or erose, thinly hispid-hirsute, about the length of the scale.—Fields, E. Mass. (Nat. from Eu. early in the century.)

[++][++] Part or usually all of the culms much shorter than the leaves.

91. C. nìgro-marginàta, Schwein. Leaves mostly stiffer than in n. 90, often broader, and some of the culms prolonged; perigynium smooth or nearly so, shorter beaked; scales purple-margined, giving the spikes a very dark or variegated appearance, considerably larger and longer than in the last.—Dry hillsides, N. J., and southward; local.

[*] 7.—[+] 3. Triquétræ.

92. C. pubéscens, Muhl. Strict, 1–2° high, pubescent throughout; leaves flat and soft, shorter than the culm; spikes 2–4, the lower 1 or 2 short-peduncled, and about ½´ long, loosely flowered, erect; perigynium very hairy, conspicuously beaked and minutely toothed, straight, about the length of the truncate and rough-cuspidate thin scale.—Copses and moist meadows, N. Eng. to Ky., and westward; frequent.

[*] 8. Phyllostáchyæ.

93. C. Jamèsii, Schwein. (Pl. 5, fig. 17–21.) Diffuse, 6–10´ high; leaves very narrow (1´´ or less), much surpassing the culm; spike very small, the staminate portion inconspicuous, the pistillate flowers 1–3 and loosely disposed; perigynium globular, produced into a very long and roughened nearly entire beak; scale narrow, the lowest often 1–2´ long, the upper often shorter than the perigynium. (C. Steudelii, Kunth.)—Woods, N. Y. to Ill., and southward; frequent.

94. C. Willdenòvii, Schkuhr. Lower, stiffer, the leaves broader and pale; spike larger, the pistillate flowers 3–9, compact; perigynium bearing a prominent two-edged very rough beak; scales chaffy, nerved, as broad as and somewhat longer than the perigynium, or the lowest rarely overtopping the spike.—Copses, Mass. to Mich., and southward; rare.

95. C. Báckii, Boott. Forming dense mats; leaves still broader (2´´ or more), very abundant; staminate flowers about 3; pistillate 2–5; perigynium more gradually beaked, smooth throughout; scales very broad and leaf-like, all exceeding the culm and entirely enveloping the spike.—W. Mass. to Ohio, and far westward; local and rare, especially eastward.

[*] 9. Leptocéphalæ.

96. C. polytrichoìdes, Muhl. Capillary, erect or slightly diffuse, 6–18´ high; leaves mostly shorter than the culm; spike 2–4´´ long, linear, the staminate portion very small; perigynium thin and green, nerved, about twice longer than the obtuse caducous scale.—Bogs; common.

[*] 10. Physocéphalæ.

97. C. Fràseri, Andrews. Cespitose; culm 6–15´ high, naked or the lower portion included in loosely sheathing abortive leaves, smooth and stiff; leaves 1´ broad or more, destitute of midrib, very thick and persistent, pale, 1–2° long; spike whitish; perigynium ovoid, faintly nerved, much longer than the scale.—Rich mountain woods, Va. and southward; very local and rare. A most remarkable plant.

98. C. chordorhìza, Ehrh. Very extensively stoloniferous; culm mostly erect, 1–1½° long; leaves involute, shorter than the culm; perigynium globular, very strongly nerved, short-pointed and entire, about the length of the acute scale.—Cold bogs and soft lake-borders, Vt. to Iowa, and northward; infrequent. (Eu.)

99. C. stenophýlla, Wahl. Stiff, 3–8´ high; leaves involute and shorter than the culm; perigynium ovate, flat on the inner face, lightly nerved, gradually contracted into a short and entire rough-edged beak, tightly enclosing the achene, at maturity longer than the hyaline acutish scale.—Dry grounds, Thayer Co., Neb. (Bessey); Emmet Co., Iowa (Cratty), and westward. (Eu).

[*] 11.—[+] 2. Vulpìnæ.

[++] Beak shorter than or about as long as the body of the perigynium.

100. C. conjúncta, Boott. Strict but rather weak, 1½–3½° high; culm soft and sharply triangular or nearly wing-angled, becoming perfectly flat when pressed; leaves soft, about 3´´ broad; head 1–3´ long, interrupted, often nearly green, infrequently bearing a few setaceous bracts; perigynium lance-ovate, light colored, whitish and thickened below, the beak lightly notched and roughish, about equalling or a little exceeding the cuspidate scale.—Swales and glades, N. J., Ky., and westward; usually rare.

[++][++] Beak twice the length of the body of the perigynium or longer.

101. C. stipàta, Muhl. Stout, 1–3° high, in clumps; culm rather soft, very sharp; head 1–3´ long, rarely somewhat compound at base, interrupted, the lowest spikes often ½´ long; perigynium lanceolate, brown-nerved, the beak toothed and roughish, about twice the length of the body, and much longer than the scale.—Swales; common and variable.

102. C. crus-córvi, Shuttlew. Stout, glaucous, 2–3° high; culm rough, at least above; leaves flat and very wide; head much branched and compound, 3–6´ long; perigynium long lanceolate, the short base very thick and disk-like, the roughish and very slender beak thrice the length of the body or more, 3–4 times the length of the inconspicuous scale.—Swamps, S. Minn. to Neb. and Ky., and southward; rare northward.

[*] 11.—[+] 3. Multiflòræ.

[++] Spikes conspicuously panicled.

103. C. decompósita, Muhl. Stout, exceedingly deep green, 1½–3° high, in stools; culm very obtusely angled, almost terete below; leaves firm, channelled below, longer than the culm; head 2–4´ long, the lower branches ascending and 1–2´ long; perigynium very small, round-obovate, few-nerved, hard and at maturity shining, the abrupt short beak entire or very nearly so; scale acute, about the length of the perigynium.—Swamps, N. Y. to Mich., and southward; local.

[++][++] Spikes in a simple or nearly simple head.

[=] Leaves very narrow (1´´ broad or less), becoming more or less involute.

[=][=] Leaves broader and flat (occasionally involute in n. 106).

a. Scales very sharp, mostly rough-tipped.

1. Perigynium large (2´´ long or more), nerveless on the inner face.

105. C. alopecoídea, Tuckerm. Stout but rather soft, 2–3° high; culm rather sharp, thick and soft in texture; leaves 2–3´´ wide, about the length of the culm, very green; head 1½´ long or less, sometimes green, and occasionally a little compound, the spikes many and compactly or somewhat loosely disposed or the lowest often separate and all mostly short-oblong; perigynium ovate, tapering into a rough beak, very prominently stipitate, with a few brown nerves on the outer face, ascending, about equalling or a little exceeding the scale.—Open swales, N. Y., Penn., and Mich.; local. In aspect like n. 101.

Var. sparsispicàta, Dewey. Weak, the leaves much narrower and lax; head 1–3´ long and linear or nearly so, the spikes smaller and separated or scattered.—S. E. Mich. (Cooley, Clark); little known.

106. C. grávida, Bailey. Lower and the culm thinner and more sharply angled, 1–2° high; leaves rather narrower and firmer, shorter than the culm; head short, always simple, globular or short-oblong, the lowest spikes rarely distinct; spikes few (4–7), globular, or broader than long; perigynium broadly ovate, nearly twice larger, sessile, plump and somewhat polished at maturity, prominently spreading.—N. Ill. to Iowa and Neb.—Var. laxifòlia, Bailey. Much larger, 2–3½° high; leaves broader (about ¼´) and lax; head large and dense, ovoid or oblong, scarcely interrupted. N. Ill. to Dak.

2. Perigynium very small, mostly nerved on the inner face.

107. C. vulpinoídea, Michx. Mostly rather stiff, 1–2½° high; culm very rough, at least above; leaves various, mostly flat and longer than the culm; head 1–4´ long, usually much interrupted and frequently somewhat compound, varying from dull brown to almost green at maturity, commonly provided with many very setaceous short bracts; spikes very numerous, ascending and densely flowered; perigynium ovate or lance-ovate, mostly ascending.—Low places, variable; very abundant, especially northward.

b. Scales blunt, smooth and hyaline-tipped.

108. C. Sartwéllii, Dewey. Stiff and strict, 1½–2½° high; leaves produced into a long slender point, mostly shorter than the culm; staminate flowers variously disposed, frequently whole spikes being sterile; head 1–3´ long and rather narrow, the individual spikes usually clearly defined, or occasionally the head interrupted below, tawny-brown; perigynium elliptic or lance-elliptic, nerved on both sides, very gradually contracted into a short beak; scale about the length of the perigynium. (C. disticha, last ed.)—Bogs, central N. Y., west and northward; frequent.

C. arenària, Linn. Extensively creeping, 1° high or less; leaves very narrow and very long-pointed, shorter than the culm; head about 1´ long, dense or sometimes interrupted, ovoid or oblong; spikes few to many, those at the apex of the head usually staminate, the intermediate ones staminate at the summit, the lowest entirely pistillate and subtended by a bract about 1´ long; perigynium very strongly nerved on both faces, wing-margined above, sharply long-toothed, about the length of the scale.—Sea-beaches near Norfolk, Va. (McMinn). (Adv. from Eu.)

[*] 11.—[+] 5. Muhlenbergiànæ.

[++] Heads narrow, the spikes scattered (or often aggregated in C. muricata.)

[=] Perigynium almost terete.

109. C. tenélla, Schkuhr. Exceedingly slender, 6´–2° high, in tufts; leaves flat, soft, and weak, mostly shorter than the culm; spikes 1–3-flowered, or the terminal 4–6-flowered, all distinct and scattered on the upper part of the culm, the bracts obsolete or the lowest present and very short; perigynium elliptic-ovate, very plump, finely nerved, the minute beak entire, longer than the white scale, usually at length splitting and exposing the blackish achene.—Cold swamps, N. Eng. to Penn., and far westward; common. (Eu.)

[=][=] Perigynium flattish.

110. C. ròsea, Schkuhr. Always slender and weak, erect, 1–2½° high, exceeding the narrow leaves; spikes 5–8, 6–14-flowered, the upper 3–4 aggregated, the others 3–9´´ apart, the lowest usually with a setaceous bract; perigynium lance-ovate, thin and shining, nerveless, scarcely margined, rough on the edges above, perfectly squarrose, very green, about twice longer than the translucent white scale.—Rich woods, N. Eng. to Minn. and Neb.; frequent.—Var. radiàta, Dewey. Lower and much more slender, the culms sometimes almost capillary; spikes 2–5, scattered, 2–4-flowered; perigynium mostly narrower and more ascending. Open places and drier woods; common.

Var. Texénsis, Torr. Very slender but strict, 1° high or less; spikes 3–4, all contiguous or the lower ones approximate, 2–6-flowered; perigynium lanceolate, the base prominently spongy, smooth or nearly so, conspicuously divaricate.—Dry places, S. Ill. (Schneck), and southward.

Var. retrofléxa, Torr. Often rather stiff, 1–1½° high; spikes 4–8, the upper ones aggregated, the lower 1 or 2 separated and commonly subtended by a conspicuous bract, often brownish; perigynium ovate, smooth throughout, very prominently corky and swollen at the base, which is frequently contracted almost to a stipe, at maturity usually widely spreading or reflexed; scale brownish and sharp, at length deciduous. (C. retroflexa, Muhl.)—Copses, throughout; rare northward.

111. C. sparganioìdes, Muhl. Stouter, stiff; culm 2–3° high; leaves very broad (usually ¼´ or more) and flat, their sheaths conspicuously clothing the base of the culm; spikes 6–10, the 2 or 3 upper ones contiguous, the remainder entirely separate, very green, oblong or short-cylindric, the lowest often compound, all truncate at top; perigynium ovate, wing-margined, rough on the short beak, often obscurely nerved on the outer face, considerably longer than the rough-pointed scale.—Rich woods; frequent.

[++][++] Heads short-oblong or globular, the spikes all aggregated, or only the lowest one or two separate.

[=] Plant very stiff throughout.

112. C. Muhlenbérgii, Schkuhr. Pale, growing in small tufts, 1–2½° high; culms much prolonged beyond the few narrow and at length involute leaves; head {3/4}´ long or less, the individual spikes clearly defined; spikes globular, 4–8; perigynium nearly circular, very strongly nerved on both faces, broader than the rough-cuspidate scale and about as long.—Open sterile soils; frequent.—Var. enérvis, Boott. Perigynium nearly or entirely nerveless. Southeastern N. Y., and southward; rare.

[=][=] Plant strict but not stiff.

113. C. cephaloídea, Dewey. Lax, very green, 2–3° high; leaves broad (2–3´´) and thin, shorter than the long culm; head rather loose, ¾´ 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. Mass. to Mich.; frequent.

114. C. cephalóphora, Muhl. Mostly smaller and stricter, pale; leaves half as wide or less; head small, rarely ½´ 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. angustifòlia, Boott. Low, 8´ high or less; leaves very narrow; head smaller, usually tawny; perigynium mostly broader.—West and southward; rare.

[*] 11.—[+] 6. Diòicæ.

[++] Perigynium nerveless or very nearly so.

115. C. capitàta, 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. gynòcrates, Wormsk. Stiff but very slender, 3–6´ high, diœcious; 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.

[*] 12. Hyparrhènæ.—[+] 1. Elongàtæ.

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

118. C. echinàta, Murray, var. cephalántha, 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 Mass. (Morong), and westward to L. Superior; rare.—Var. conférta, 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. micróstachys, 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. angustàta, 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. canéscens, L. Stiff and rather stout, 1–2½° 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. vulgàris, 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. alpícola, Wahl. Low and stiff, or at lower altitudes 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.)

120. C. Norvégica, 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. tenuiflòra, Wahl. Very slender and diffuse, 1–1½° 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. trispérma, 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. Deweyàna, Schwein. Weak, 1–1½° 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. bromoìdes, 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 diœcious; 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. Ovàles.

[++] Perigynium ovate-lanceolate, with winged margins.

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

126. C. Muskinguménsis, 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. tribuloìdes, 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. turbàta, 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 (¼ to rarely ½´ long), contracted below; perigynium ascending and more appressed, the points therefore not conspicuous. Woods, throughout; rare.—Var. redúcta, 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. Bébbii, Bailey. Stiff or rather slender, erect, 1–2½° high; head dense, ovoid or oblong (¼–¾´ 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. cristàta, Bailey. Stout and stiff, 1½–3° 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. scopària, Schkuhr. Rather slender but erect, 1–2½° 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.

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

[=] Head silvery-brown, silvery-green, or silvery-whitish.

129. C. adústa, Boott. Very stiff and stout, 1½–2½° 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. fœ̀nea, 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. perpléxa, 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. silícea, 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. fœnea, var. sabulonum, last ed.; C. straminea, var. moniliformis, Tuckerm.)—Sands of the sea-shore, Maine to N. J.; frequent.

[=][=] Head dull brown or green (usually somewhat silvery in var. fœnea of n. 132).

132. C. stramínea, 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.

Var. brèvior, Dewey. (Pl. 6, fig. 6–10.) Culm always stiff, 1½–2½° high, longer than the stiff long-pointed leaves; spikes 3–8, all distinct, contiguous or more or less separated, large (3–5´´ broad), globular, the head always short and erect; perigynium orbicular or ovate-orbicular, often cordate at base, mostly very broadly winged. (C. straminea, and vars. typica, hyalina, and Meadii, last ed.)—Dry soils, throughout; common.

Var. apérta, Boott. Culm slender but strict below the head, 1–2° high, growing in dense tufts; leaves very narrow, usually much shorter than the culm; spikes 4–6, large, heavy, much contracted below, usually all separated, becoming rusty, disposed in a weak or nodding head; perigynium narrowly ovate.—Bogs, throughout; rare westward. Transition to n. 128, from which the ovate perigynia distinguish it.

Var. invìsa, W. Boott. Culm very slender, weak above; leaves very narrow with exceedingly long thin points, about the length of the culm; spikes small (3´´ broad or less), ovate, variously disposed in dense or open heads or sometimes the lowest remote or even subradical, rusty, the lower ones subtended by filiform bracts 2–5´ long.—Swales near the sea-board, Maine to Del.; infrequent. Apt to be confounded with n. 128.

Var. alàta, Bailey. Culm very stiff, 1½–3° high, longer than the stiff leaves; spikes very large, oblong or conical, always pointed, usually all contiguous, green or sometimes becoming tawny; perigynium orbicular or orbicular-obovate, very abruptly contracted into a short beak which is prominent in the spike. (C. alata, Torr.)—Swales, Mass. to Ill., and southward; rare and uncharacteristic far inland.

Var. cumulàta, Bailey. Culm very stiff, 2–3° high, greatly exceeding the firm leaves; spikes 5–30, all aggregated or densely capitate, green, widely divergent, pointed above, very abruptly contracted or even truncate at base, very densely flowered; perigynium small, broad, very obscurely nerved, the points inconspicuous.—Dry grounds, Penn. to N. Eng., and northward; rare.

Var. fœ̀nea, Torr. Culm very stiff, longer than the leaves, 1–2° high; spikes 4–8, contiguous or separated, never densely aggregated, prominently contracted both above and below, very densely flowered, green, or often silvery-green. (C. fœnea, last ed., excl. vars.; not Willd.)—Near the sea-coast; frequent.

C. leporìna, L. Distinguished from C. straminea, var. brevior, as follows:—Usually lower; spikes rusty-brown, ovoid or oblong, erect or appressed, more or less contracted both above and below, contiguous in an interrupted head 1´ long or less; perigynium lance-ovate, thin, very narrowly margined, erect and appressed, obscurely nerved.—About Boston (W. Boott, Morong). (Adv. from Eu.)

[*] 12.—[+] 3. Cyperoídeæ.

133. C. sychnocéphala, Carey. Erect, 3–18´ high, leafy; head ½–1´ long; perigynium very slender, faintly nerved, 5–6 times longer than the exceedingly small achene, mostly a little longer than the sharp scale.—Glades, central N. Y. to Minn., and far westward; rare.

11. Tripsacum. Spikelets monœcious, the staminate above in the spike.

12. Rottbœllia. One spikelet of each pair sterile and shortly pedicelled, the other fertile, sessile and sunk in the rhachis.

Tribe IV. ANDROPOGONEÆ. Spikelets in pairs or threes on the (usually jointed and bearded) rhachis of a spike or branches of a panicle, one sessile and fertile, the lateral pedicelled and often sterile or rudimentary; 2 upper glumes smaller and hyaline, that of the fertile flower mostly awned.

13. Erianthus. Spikelets in pairs, spicate, all alike fertile, involucrate with a silky tuft.

14. Andropogon. Spikelets spicate, in pairs, the pedicellate sterile or rudimentary; rhachis bearded.

15. Chrysopogon. Spikelets in open panicles, in pairs or threes, only the sessile fertile.

Series B. Rhachis of the spikelet usually jointed above the persistent lower glumes (jointed below the glumes only in n. 19, 31, and 36). Spikelets 1–many-flowered, the uppermost flowers often imperfect or rudimentary.

Tribe V. PHALARIDEÆ. Glumes 5, only the uppermost fertile, the 2 middle ones rudimentary or empty or staminate; palet 1-nerved. Panicle mostly contracted and spike-like.

16. Phalaris. Middle glumes mere rudiments each side of the shining triandrous flower.