SEDGE FAMILY 115 



Perigynia lance-ovate, the beak shorter than the bodj-; longer bracts less than 1 dm. 

 long, with yellowish brown margins at base. 

 Perigynia nerveless ventrally, tawny at orifice. 37. C. athrostachya. 



Perigj-nia nerved ventrally, hyaUne at orifice. 38. C. tenuirostris. 



Bracts not conspicuous, rarely sUghtly exceeding the head. 



Beak of the perigj-nia flattened and serrulate to tip, often strongly bidentate. 



Scales about the length of the perigj-nia and nearly of the same width above, 

 the perigj-nia nearlj- entirely concealed. 

 Head stiff, the spikes approximate. 



Perigj-nia less than 5.5 mm. long, at most faintly nerved on inner face, 

 looselj' ascending; spikes suborbicular; lower bracts prominent, stiff. 



39. C. aclusta. 

 Perigj-nia 5. .5-7 mm. long, finely manj'-nerved on inner face, appressed; 

 spikes oblong-elUptic: bracts not stiff. 40. C. petasata. 



Head not stiff, flexuous or moniliform. 41. C. aenea. 



Scales shorter than perigj-nia and noticeably narrower above, the upper part of 

 perigj-nia largelj- exposed. 

 Perigj-nia subulate to lanceolate, at lea-st 2 l-i times as long as wide. 

 Perigj-nia subulate, the margin at the base almost obsolete. 



42. C. Crawfordii. 

 Perigj-nia lanceolate, the margin conspicuous to the base. 



43. C. scoparia. 

 Perigynia ovate-lanceolate or broader, at most twice as long as wide. 



Perigj-nia narrowly to broadlj- ovate, 3—1 mm. long. 



Perigj-nia brownish; spikes closely aggregate, roimded at base. 



44. C. Bebbii. 

 Perigj-nia green; spikes contiguous to widelj- separate, usually tapering 



at base. 

 Leaf-blades 2.5 mm. wide or less; perigj-nia spreading-ascending; 



culms slender. 45. C. tenera. 



Leaf-blades 2-6 rmn. wide (averaging 4 mm. ) ; perigj-nia appressed- 

 ascending; culms stout. 46. C. tincta. 



Perigj-nia ovate or broader, 3.75-6 mm. long. 



Perigj-nia thick, abruptly short-beaked; scales little, if at all, tinged 



with brownish red. 47. C. bretior. 



Perigj-nia thin, tapering to the beak; scales strongly tinged with chest- 

 nut-brown. 48. C. Egglestonii. 

 Beak of the perigynia slender, terete and scarcelj-, if at all, serrulate towards tip, 

 obliquelj- cut, at times becoming obscurely bidentate. 

 Scales about the length of the perigj-nia, and "of nearly the same width above, the 

 perigj-nia nearlj- entirelj' concealed. 

 Culms and head stiff and rigid. 



Culms 1-3 dm. high, in large stools; scales strongly tinged with reddish 



bro-svn ; perigj-nia lanceolate. 49. C. phaeocephala. 



Culms taller, not in large stools; scales Ughter-colored ; perigynia ovate, 

 in age golden j-ellow at base. 50. C. xeran'tica. 



Culms slender; head flexjious or moniliform. 



Scales light reddish b'rown tinged. 51. C. practicola. 



Scales chestnut-brown tinged. 52. C. Piperi. 



Scales shorter than perigj-nia and noticeablj' narrower above, the upper part of 

 perigj-nia largelj- exposed. 

 Perigj-nia thin and membranous, except where distended by the achene. 

 Perigj-nia 3.5-5 mm. long; culms slender. 



Perigj-nia lance-ovate, verj- narrowlj- margined, spreading; culms 



biennial. 53. C. microptera. 



Perigj-nia ovate, stronglj- margined, appressed; culms annual. 



54. C. festirella. 

 Perigj-nia 4.5-6 mm. long; culms low. 



Perigj-nia lanceolate to broadlj' ovate, nerveless or nearlj- so on inner 

 face, the beaks conspicuous; culms slender, ascending oV decumbent. 



55. C. nubicola. 

 Perigj-nia narrowly lanceolate, finely nerved on inner face, the beaks 



appressed; culms stiff, erect. 56. C. ebenea. 



Perigj-nia stronglj^ plano-convex, the walls thick. 



Spikes densely capitate; beak of the perigj-nia obliquely cut, dark-tipped. 



57. C. pachystachya. 

 Spikes not capitate; beak of the perigj-nia bidentate, reddish-tipped. 



58. C. Preslii. 



17. C-^XESCENTES. 



Spikes androgj-nous ; perigj-nia unequall J- biconvex. 59. C disperma. 



Spikes gj-naecandrous ; perigj-nia plano-convex. 



Lowest bract bristle-like, much prolonged, many times exceeding its 1-5-flowered 



spike; spikes widely separate. 60. C. trisperma. 



Lowest bract much shorter or none; spikes several-manj--flowered, the upper approxi- 

 mate. 

 Spikes 2-4, subglobose, closelj- approximate, forming an ovate or subglobose head; 



perigj-nia scarcely beaked; scales white-hj-aline. 61. C. lenuiflora. 

 Spikes one-man J-, the lower more or less strongly separate; head elongate; peri- 

 gj-nia shortly to strongly beaked; scales darker. 

 Perigj-nia broadest near middle; beak short, smooth or moderately serrulate 



