CAREX KEY. SEDGE FAMILY. 355 



Perigynia ovate, abruptly beaked. 



Leaves flat, l /2"-i l / 2 " wide; culms strict, erect. 39. C. Lachenalii. 

 Leaves involute, J4"--M" wide; culms weak, slender. 40. C. amphigena. 

 Perigynia lanceolate, long-tapering. 41. C.glareosa. 



Terminal spike little clavate ; culms usually very rough. 42. C. Heleonqstes. 

 Lower spikes widely separate, 2"-2^" wide. 43. C.norvegica. 



Perigynia beak serrulate, or if smooth the scales acutish to cuspidate and scarcely if at 



all reddish-brown tinged ; lower spikes remote. 

 Glaucous; leaves i"-2" wide; spikes many-flowered, the scarcely beaked appressed- 



ascending perigynia with emarginate or entire orifice. 44. C. canescens. 



Not glaucous; leaves /4"-i/4" wide; spikes fewer-flowered, the distinctly beaked, 



loosely spreading perigynia with minutely bidentate orifice. 45. C. brunnescens. 

 Perigynia ovate, broadest near base, the beak conspicuous, strongly serrulate. 46. C. arcta. 



14. DEWEYANAE. 

 Spikes oblong-ovoid; perigynia nerveless or nearly so, sharply margined above; achenes i" long; 



scales greenish-white. 47. C. Deweyana. 



Spikes linear ; perigynia noticeably or strongly nerved, little margined above ; achenes %" long or 

 less ; scales brownish-tinged. 48. C. bromoides. 



15. STELLULATAE. 



Spike one (rarely with a small additional one). 49. C. exilis. 



Spikes more than one. 



Perigynia soon ruptured by elongating achene and appearing glume-like. 50. C. elachycarpa. 

 Perigynia not soon ruptured, remaining normal. 

 Perigynia broadest near base, the beak serrulate. 



Perigynia beak l A~ l /3 length of body, the teeth very short, the suture on inner side incon- 

 spicuous ; scales very obtuse to acutish. 

 Leaves flat, l / 2 "-i" wide, usually shorter than culm; perigynia little nerved. 



51. C. interior. 

 Leaves usually involute, >4" wide, usually exceeding culm; perigynia strongly nerved. 



52. C. Howei. 

 Perigynia beak longer, strongly bidentate, the suture conspicuous ; scales sharper. 



Perigynia body lanceolate to broadly ovate, narrowed into beak more than half its 



length ; perigynia usually inconspicuously nerved on inner face. 53. C. Leersii. 

 Perigynia body suborbicular, abruptly contracted into beak less than half its length ; 



perigynia conspicuously nerved on inner face. 



Perigynia lightly nerved on both faces ; scales acute to short acuminate ; leaves 



usually less than i" wide; culms slender, sharply triangular. 54. C.incomperta. 



Perigynia strongly nerved on both faces ; scales acutish to acute ; leaves i"2" 



wide, the lower very short ; culms stout, obtusely triangular. 55. C. atlantica. 

 Perigynia broadest near middle, the beak smooth. 56. C. rosaeoides. 



1 6. OVALES. 

 r. Perigynia subulate, at least three times as long as wide, less than 54" wide, wing near base almost 



obsolete. 

 Bracts much elongated, many times exceeding head, leaf-like; perigynia 2 l / 2 " long, the beak 2-3 



times length of body. 57. C.sychnocephala. 



Bracts much shorter and reduced ; perigynia 2*4" long or less. 



Tips of perigynia equalling or scarcely exceeded by the obtuse or acute dark brown scales ; 



leaves i l /^"-2" wide; culms 2o'-4o' high. 58. C.oronensis. 



Tips of perigynia conspicuously exceeding the acute or acuminate light brown scales; leaves 



y 2 "-iy 2 " wide ; culms $'-24' high. 59. C, Crawfordii. 



2. Perigynia lanceolate to reniform ; wing near base narrow to very wide, but never almost obsolete. 

 A. Perigynia narrowly to broadly lanceolate, at least 2 l / 2 times as long as broad; tips of peri- 



gynia prominently exceeding scales. 

 Spikes z"-T l / 2 " long; p 



perigynia 354" long or less; achene short-oblong. 



Leaves at most 1^/2" wide, those of sterile shoots few, ascending. 60. C.scoparia. 

 Leaves broader, those of sterile shoots very numerous, widely spreading. 



Tips of perigynia appressed or ascending; spikes 3^2 "-6" long. 61. C.tribuloides. 

 Tips of perigynia widely spreading or recurved ; spikes 2"-$" long. 



Inflorescence dense, oblong ; culm stiff, stoutish. 62. C. cristatella. 



Inflorescence loose, elongate ; culm weak, slender. 63. C. projecta. 



Spikes ?y 2 "-13" long; perigynia 3^2 "-5" long; achenes linear-oblong. 64. C.muskingumensis. 

 B. Perigynia ovate-lanceolate or broader, at most twice as long as broad, or if narrower tips of 



perigynia equalled by scales. 

 a. Perigynia strongly exceeding scales or if nearly equalled by them much wider. 



t Perigynia narrowly to broadly ovate, \y 2 "-2" long, nerveless or few-nerved on inner face, 



the tips not appressed. 



Perigynia brownish ; spikes closely aggregated, rounded at base. 65. C. Bebbii. 

 Perigynia green ; spikes contiguous to widely separate, usually clavate at base. 

 Leaves i" wide or less. 66. C . straminea. 



Leaves iK"-3" (averaging 2") wide. 67. C. normally. 



tt Perigynia ovate to reniform, 2" or more long, or if shorter with closely appressed tips. 

 Spikes closely aggregated, the scales dark brown or blackish. 68. C. macloviana. 

 Spikes approximate to widely separate, the scales lighter. 

 Perigynia spreading-ascending ; spikes green or brownish. 



Spikes approximate or scattered, the head stiff ; scales obtuse or acutish. 



Perigynia 2"-2f4" long, thickish, nerveless or obscurely nerved on inner face. 



69. C. festucacea. 

 Perigynia 2^"-3?4" long, very thin, prominently about lo-nerved on inner 



face. 70. C. Bicknellii. 



Spikes in a moniliform flexuous head ; scales long-pointed. 



71. C. hormathodes. 



