CYPERACEAE 



205 



Perigynia barely 4 mm. long, each with a long 2-toothed beak. 

 Perigynia 5-6 mm. long, each with a short entire or nearly entire 

 beak. 



XXIV. TRIQUETRAE. 



Leaf-blades scabrous : perigynia ovoid, somewhat longer than the scales. 

 Leaf-blades pubescent : perigynia oblong or elliptic, about twice as long as 

 the scales. 



XXV. PHYSOCEPHALAE. 

 A single species in our range. 



XXVI. SCIRPINAE. 

 A single species in our range, 



XXVII. PHYLLOSTACHYAE. 



Body of the perigynium oblong ; beak flattened. 

 Body of the perigynium globose ; beak subulate. 



XXVIII. LEPTOCEPHALAE. 



XXIX. FILIFOLIAE. 



A single species in our range. 



A single species in our range. 



XXX. VULPINAE. 



Spikes crowded into an oblong panicle : beak of the perigynium as long as 



the body to twice as long. 

 Spikes in a large branching panicle : beak of the perigynium 2-3 times as 



long as the body. 



XXXI. MULTIFLORAE. 



Spikes very numerous in branched decompound clusters, small. 

 Spikes several or many in narrow simple or slightly compound clusters. 

 Scales acuminate, cuspidate or awned. 

 Perigynia 3-5 mm. long. 

 Perigynia 2-3 mm. long. 



Leaves as long as the stem or longer : perigynia dull yellow to 

 brown. 

 Perigynia ovate, nerveless or faintly 1-3-nerved, 1.5 mm. long. 

 Perigynia nearly orbicular, delicately nerved, fully 2 mm. long. 

 Leaves shorter than the stem : perigynia bright yellow. 

 Scales blunt, scarious-tipped. 



XXXII. MUHLENBERGIANAE. 



Spikes separated or the upper approximate : perigynia mostly radiating or 

 reflexed. 

 Leaf-blades 1-3 mm. wide. 



Perigynia ovate-lanceolate or oblong-lanceolate, 2-3 mm. long. 

 Perigynia stellately radiating or ascending. 



Perigynia radiately spreading, mostly over 3 mm. long, gradually 



narrowed to the apex. 

 Perigynia ascending, mostly less than 3 mm. long, each abruptly 

 narrowed into a beak. 

 Perigynia reflexed, at least when mature. 

 Perigynia narrowly lanceolate, 3-4 mm. long. 

 Leaf-blades 5-9 mm. wide. 

 Spikes all aggregated or the lower separated : perigynia spreading or as- 

 cending. 

 Perigynia 2 mm. long or shorter, nerveless or faintly few-nerved. 

 Leaf-blades 2-3 mm. wide : perigynia ovate. 

 Leaf-blades 1-2 mm. wide : perigynia orbicular-ovate. 

 Perigynia 3 mm. long, strongly nerved or nerveless. 

 Bracts very short. 

 Bracts foliaceous, much exceeding the spikes. 



XXXIII. ELONGATAE. 



Perigynia radiately spreading or reflexed when mattire. 

 Perigynium distinctly nerved on both faces ; beak rough. 



Perigynium lanceolate : beak more than % as long as the body. 

 Perigynium ovate : beak about % as long as the body, abrupt. 

 Perigjmium faintly nerved only on the outer face ; beak smoothish. 

 Perigynia appressed or ascending, at least not radiating. 

 Perigynia oval to ovate-oval, about 2 mm. long. 

 Perigynia linear-lanceolate, 4-5 mm. long. 



XXXIV. OVALES. 

 A. Perigynia much longer than broad. 



Perigynia lanceolate or ovate-lanceolate, 2-5 times as long as wide. 

 Spikes green-brown, blunt. 

 Spikes bright brown, pointed. 

 Perigynia ovate, or if narrower not more than twice as long as wide, 

 a. Perigynia spreading or ascending. 



Spikes longer than thick, narrowed at the base : perigynia ascend- 

 ing, slightly longer than the scales. 

 Spikes as thick as long or shorter, rounded at the base: perigj'nia 

 spreading, much longer than the scales. 



77. C. iiinhdlata. 



78. C. planostachys. 



79. C. Chapmanii. 



80. C. dasycarpa. 



81. C. Frascri. 



82. C.picta. 



83. C. Willdenovii. 



84. C. Jamesii. 



85. C. leptalea. 



86. C.filifoUa. 



87. C. stipata. 



88. a Crus-CorvL 



89. C. decomposita. 



90. C. gravida. 



91. C. vulpinoidea. 



92. C. triangularis. 



93. C. xanthocarpa. 



94. C. Sartwellii. 



95. C. rosea. 



96. C. radiata. 



97. C. retroflexa. 



98. C. Texensis. 



99. C. sparganioides. 



100. C. cephalophora. 



101. C. Leavenworthii. 



102. C. Muhlenbergii. 



103. C. Arkansana. 



104. 

 105. 

 106. 



107. 

 108. 



109. 

 110. 



111. 

 112. 



C. sterilis. 

 C. Atlantica. 

 C. interior. 



C. hrunnescens. 

 C. bromoides. 



C. tribuloides. 

 C. scoparia. 



C. straminea. 



C. mirabilis. 



