The Flora of the Cayuga Lake Basin 111 



PAGE 



/. Main leaves 6-12 mm. wide, glaucous ; perigynia 3-4 

 mm. long; pistillate spikes bearing 1-2 staminate 



flowers at the base 70. C. laxiculmis 126 



/. Main leaves 2-5 mm. wide, very green; perigynia 

 2.5-2.8 mm. long; pistillate spikes without staminate 



flowers 71. C. digitalis 126 



Perigynia obtusely triangular, the faces more convex ; nerves 



various. 

 k. Perigynia narrowed or substipitate at base ; orifice or 

 beak often more or less oblique ; spikes remote or con- 

 tiguous. (2d k, p. 112.) 

 /. Perigynia 40-50-nerved, slender-beaked; scales rough- 

 awned. 

 m. Sheaths pubescent ; perigynia 4-5 mm. long ; leaves 



3-7 mm. wide 72. C. Hitchcockiana 126 



m. Sheaths glabrous ; perigynia 4 mm. long ; leaves 



2-4.5 mm. wide 73. C. oligocarpa 127 



/. Perigynia 15-30-nerved; scales subtruncate, some apic- 

 ulate. 

 m. Plant stoloniferous ; leaves long and narrow; spikes 



very distant 81. C. tetanica 128 



m. Plant cespitose ; leaves shorter and often broader ; 

 spikes aggregated or distant. 

 n. Perigynia strongly and often sharply (21) 24-45- 

 nerved. 

 o. Perigynia with a short and rather broad apex or 

 point which is turned more or less to one side. 

 p. Spikes alternately flowered; scales truncate or 

 refuse, muticous, subflabellate at apex ; stam- 

 inate spike very slender, inconspicuous, equal- 

 ed or exceeded and often hidden by the ag- 

 gregated pistillate spikes ; culms broad, almost 

 winged, the angles smooth or slightly erose ; 

 bracts broad, erect; leaves very broad (10-40 



mm. wide) 74. C. albursina 127 



p. Spikes denser, perigynia much overlapping ; 

 scales subtruncate, rounded, or acute, usu- 

 ally cuspidate ; staminate spike conspicuous 

 or inconspicuous ; culms narrower, less broad- 

 ly margined, the angles more or less erosely 

 or retrorsely serrulate-scabrous ; bracts and 

 leaves narrow or sometimes rather broad. 

 q. Basal sheaths brown; foliage pale; bracts 

 usually overtopping the culm; spikes more 

 or less aggregated at summit of culm; 

 scales pale ; axis of spikes usually smooth ; 

 tip of perigynium either abruptly or only 



slightly bent 75. C. blanda 127 



q. Basal sheaths purple, but often weathering 

 away; foliage brighter or yellow-green; 

 bracts rarely overtopping the culm; spikes 

 scattered; scales often colored; axis of 

 spikes usually granulose; perigynia more 

 fusiform, the tip more strongly recurved; 

 plant generally more slender. 



76. C. laxiflora 127 



