CYPERACEAE 



177 



Perigynia lanceolate or 

 lance-subulate, tap- 

 ering into the beak, 

 many-nerved. 

 Perigynia-teeth rc- 

 flexed; perigynia 

 green, early de- 

 ciduous. 

 Perigynia-teeth not 

 reflexed; perigy- 

 nia yellowish - 

 green. 

 Perigynia broader, 

 abruptly c o n - 

 tracted into beak, 

 usually strongly 

 ribbed. 

 Perigynia less than 

 10 mm. long. 

 Perigynium 

 body 

 ovoid or 

 globose, 

 not trun- 

 c a t e 1 y 

 contracted. 

 Perigynia 

 coarsely 

 ribbed. 

 Perigynia 

 finely and 

 closely 

 ribbed. 

 Perigynia with 

 an obovoid or 

 obconic body 

 truncately 

 c o n t r a c t e c 1 

 into the prom- 

 inent beak. 

 Perigynia 10 mm. 

 long or longer. 



39. CoLLINSIAE. 



40. FOLLICULATAE. 



41. Physocarpae. 



42. PSEUDOCYPEREAE. 



43- 



Squarrosae. 



44. LUPULINAE. 



1. Arenariae, represented only by 



2. Muhlenbergianae. 



Sheaths tight, often thickened at mouth; inconspicuously if 

 at all septate-nodulose. 

 Perigynia corky-thickened at base, usually widely radi- 

 ating or reflexed at maturity. 



13 



1. C. siccata 



