CYPERACEAE 



47 



III. 



Inflorescence usually IV or more long, the 

 clusters compound. 

 Beak of the perigynium longer than the body. 

 Beak 1-2 times length of body. 

 Beak 3-4 times length of body. 

 Beak of perigynium shorter than the body. 

 Perigynium and beak 2^^ long. 

 Perigynium and beak IV^ or less long. 

 Scales acute to acuminate. 

 Leaves exceeding stem. 

 Stem exceeding leaves. 

 Scales obtusish. 

 Inflorescence usually less than IV long, the 

 clusters rather simple. 

 Clusters strongly separated. 

 Leaves \"-\Y' wide. 

 Perigynia radiating. 

 Perigynia reflexed at maturity. 

 Leaves 2V'-\\" wide. 

 Clusters aggregated. 



Heads green when mature. 

 Leaves 2"-\" wide. 

 Leaves Y'-'^l" wide. 

 Head &' or less long, the clusters hardly 

 recognizable. 

 Leaves V'-'l" wide. 

 Leave \" or less wide. 

 Head ^" or more long, the clusters rec- 

 ognizable. 

 Heads yellowish at maturity. 



IV. 



Perigynia widely spreading. 

 Perigynia not widely spreading. 



Perigynia 2-5 times as long as wide. 

 Spikes narrowly cylindric, 6"-12" long. 

 Spikes globular to short-oblong. 

 Spikes cone-shaped above. 

 Spikes bluntish. 

 Perigynia erect. 

 Perigynia spreading. 

 Perigynia less than twice as long as wide. 

 Heads greenish-brown. 

 Perigynia ovate. 

 Perigynia orbicular. 

 Heads silvery-green. 



1. C. Asa-Grayi Bailey. 2°-3° high : leaves many, 2,"-\V' wide : 

 pistillate spikes 1-2, V in diameter, perfectly globular, 10-30-flowered : 

 perigynia much-inflated, many-nerved, %"-W long. — In low, wet woods 

 near Lake City and Sibley. Pare. May-June. 



2. C. lupulina Muhl. 2°-4° high : leaves 'i,\"-\" wide : pistillate 

 spikes 2-6, oblong-cylindrical, \'-2V long, densely many-flowered, sessile 

 of short-stalked : perigynia &'-^" long, much inflated, many-nerved. — 



32. C. stipafa. 



33. C Crus-Corvi. 



31. C. conjuncta. 



35. C. vuljnnoidea. 



36. C. xanihocarpa. 



37. C. SarticeUii. 



38. C. rof^ea. 



39. C. retrofiexa. 



40. C. spa rg a no ides. 



41. C. cephaloidea. 



42. C cephalophora. 



43. C. Lfavemvorthii. 



44. C. Muhhnhergh. 

 34. C. gravida. 



45. C. sierilis. 



