CYPERACEAE 



183 



-3 



24 



Perigynia narrowly obovoid, ascending, nerved, about 



2.5 mm. long. 

 Perigynia broadly obovoid, soon squarrose, ribbed, 

 about 3.5 mm. long. 

 Rootstocks long-creeping; staminate spike long stalked; 



bracts rarely overtopping spikes. 

 Oligocarpae. 



Sheaths smooth; perigynia 2.5-4 mm - long- 

 Sheaths rough-pubescent; perigynia 4.5-5 mm. long. 

 Griseae. 



Culms strongly purplish at base; perigynia triangular in 



cross-section. 

 Culms not purplish at base or but little so; perigynia 

 circular in cross-section. 

 Perigynia 1.5 mm. wide; bract sheaths and pistillate 



peduncles rough. 

 Perigynia 2 mm. wide; bract sheaths smooth and 

 pistillate peduncles nearly so. 

 Leaves not glaucous; perigynia 4.5-5 mm. long; 



spikes 5-15-flowered. 

 Leaves glaucous; pergyinia 3-4.5 mm. long; 

 spikes 10-40-flowered. 



25. Gracillimae. 



Plants glabrous; perigynia 2.7 mm. long or less. 

 Perigynia rounded at apex, beakless. 

 Perigynia sharp pointed at apex, short-beaked. 

 Sheaths and often foliage pubescent. 



Scales except lowest obtuse or acute; spikes all gynae- 



candrous. 

 Scales acuminate to cuspidate; lateral spikes pistillate. 

 Bracts strongly sheathing; leaves 3-4 mm. wide. 

 Lower bracts only strongly sheathing; leaves 2-4 

 mm. wide. 

 Perigynia nearly 2 mm. wide, slightly inflated, 



strongly nerved. 

 Perigynia about I mm. wide, obscurely nerved. 



26. Debii.es. 



Scales tinged with reddish-brown; perigynia firm, strongly 



many-nerved. 

 Scales hyaline with green midrib or somewhat reddish- 

 brown tinged; perigynia membranous, lightly nerved. 

 Perigynia sessile or subsessile; scales obtuse or short 

 cuspidate. 

 Perigynia 6-10 mm. long, the beak subulate; scales 



hyaline margined. 

 Perigynia 4.5-6.5 mm. long, the beak less subulate; 

 scales tawny tinged. 

 Perigynia strongly stipitate; scales strongly cuspidate. 

 Flexiles, represented only by 

 Longirostres, represented only by 



89. C. conoidea. 



90. 



91. 



92. 

 93. 



94- 



95. 



96. 

 97- 



C. grisea. 

 C. glaucodea. 



C. gracillima. 

 C. prasina. 



C. formosa. 

 C. Davisii. 



C. aeslivaliformis. 

 C. aestivalis. 



98. C. oblita. 



27 



28 



