The Flora of the Cayuga Lake Basin 105 



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i. Leaves 4.5-8 mm. wide ; sheaths loose. 



j. Culms about 1 mm. in diam. below the inflorescence, not 



wing-angled; perigynia narrowly to broadly ovoid; scales 



silvery. 



k. Inflorescence short, dense ; perigynia 3.4-4 mm. long, 



1.6-2 mm. wide, narrowly ovoid, the beak equaling the 



body; plant yellowish green 12. C. ccphaloidea 116 



k. Inflorescence elongated, interrupted ; perigynia 3-3.5 mm. 

 long, 1.8-2 mm. wide, broadly ovoid-orbicular, the beak 

 shorter than the body; plant glauc©us-green. 



13. C. sparganioides 117 

 j. Culms about 2 mm. in diam. at summit, soft and wing- 

 angled ; perigynia narrowly ovoid ; inflorescence dense ; 



scales tawny at maturity 14. C. alopecoidea 117 



g. Spikes or branches of the inflorescence numerous. 



h. Perigynia plano-convex, yellowish; plant green; bracts, or most 



of them, much exceeding the spikes, setaceous; scales pale; 



scarious part of sheath transversely rugose, white. 



i. Leaves exceeding the culms ; perigynia ovoid to broadly ovoid, 



1.2-1.8 mm. wide, the beak nearly or quite as long as the 



body ; inflorescence green 15. C. vulpinoidea 117 



i. Leaves shorter than the culms; perigynia broadly ovoid, 1.6-2 

 (2.4) mm. wide, the beak much shorter than the body; 

 inflorescence stramineous at maturity. 

 /. Perigynia 2.6-3.2 mm. long, usually nerved on the outer 



face ; beak rather prominent 16. C. anncctens 117 



j. Perigynia 2.2-2.6 mm. long, usually nerveless ; beak very 

 short and point-like, and obscurely notched ; inflorescence 

 generally broader and shorter. .16a. C. a., var. xanthocarpa 117 

 h. Perigynia thick, often convex on both surfaces, brown; bracts, 

 or all but the lowermost, shorter than the spikes ; scales usually 

 fuscous, frequently not covering the perigynia ; scarious part 

 of sheath not rugose, usually colored, at least in spots. 

 i. Leaves 1-3 mm. wide; inflorescence 1.5-5 cm. long; spikes 

 obscurely branched. 

 j. Inflorescence dense, erect, appearing bristly from the radiat- 

 ing, bright, dark-colored, ovoid, 2-2.5 mm. long, perigynia ; 

 inner face of perigynia convex; scales short. 



17. C. diandra 117 

 /. Inflorescence more lax and nodding, with a more chaffy 

 appearance ; perigynia more appressed, more lanceolate, 

 duller brown, 2.5-3.5 mm. long, the inner face flat or 



concave; scales 3 mm. long 18. C. prairea 117 



i. Leaves 5-8 mm. wide; inflorescence 10-15 cm. long; spikes 



plainly branched 19. C. decomposita 118 



e. Plants with long creeping rhizomes. (See also no. 10.) 

 /. Perigynia 3-5 mm. long, thin-margined, ovoid-lanceolate, the orifice 

 strongly bidentate; inflorescence nodding; leaves 2-5 mm. wide, 



flat .20. C. Sartwellii 118 



/. Perigynia about 2 mm. long, not thin-margined, broadly ovoid, 

 turgid, plano-convex, the orifice entire ; inflorescence stiff, subcapi- 



tate; leaves narrow, involute 21. C. chordorrhisa 118 



Spikes staminate at base, rarely at both base and apex (at apex only in 

 no. 24). (Hyparrhenae.) 



