CYPERACEAE (SEDGE FAMILY) 



8 a Spikelets somewhat 2-rowed, usually more than Vz in. 



long YELLOW NUT-GRASS. (C. esculentus.) 



b Spikelets many-rowed, about % in. long 



STRAW-COLORED CYPERUS. (C. strigbsus.) 



2 DULfCHIUM DULICHIUM. (D. arundinaceum.) 



3 ELE6CHARIS. 



1 a Spike s-y-flowered NEEDLE SPIKE-RUSH. (E. acicularis.) 



b Spike lo-many flowered 2 



2 a Stems stout, usually more than i ft. high 



CREEPING SPIKE-RUSH. (E. palustris.) 

 b Stems slender, usually i ft. or less high 3 



3 a Stems 4-angled with concave sides; spike narrowly 



oblong SLENDER SPIKE-RUSH. (E. tennis.) 



b Stems not completely as in a; spike usually ovoid 



OVOID SPIKE-RUSH. (E. o-vata.) 



4 STENOPHYLLUS STENOPHYLLUS. (S. capillaris.) 



5 FIMBRfSTYLIS. 



i a Spikelets oblong, stout, chestnut brown 



MARSH FIMBRISTYLIS. (F. castanea.) 

 b Spikelets linear, slender, brown 



SLENDER FIMBRISTYLIS. (F. autumnalis.) 



6 SCfRPUS. 



1 a Spikelets in clusters appearing lateral on the stem. ... 2 

 b Spikelets in umbels 4 



2 a Spikelets 1-6 together in a cluster; scales with a short, 



straight awn CHAIR-MAKER'S RUSH. (S. americanus .) 



b Spikelets 5-20 together in a cluster ; mature scales with 



a reflexed awn or nearly awnless 3 



3 a Stems with sides much concave; scales pointed or with 



a very short awn OLNEY'S BULRUSH. (S. dlneyi.) 



b Stems with sides not much concave; scales with a re- 

 flexed awn when mature 



SALT-MARSH BULRUSH. (S. robustus.) 



4 a Spikelets covered with reddish-brown hairs 



WOOL GRASS. (S. cyperinus.) 

 b Spikelets not covered with reddish-brown hairs 5 



5 a Stems circular; involucre leaf appearing as a continua- 



tion of the stem GREAT BULRUSH. (S. vdlidus.) 



b Stems triangular; involucre leaves 3-6, not as in a 



LEAFY BULRUSH. (S. polyphyllus.) 



7 ERI6PHORUM COTTON GRASS. (E. virgin! cum.) 



8 RHYNCH6SPORA. 



i a Spikelets in several clusters scattered on the stem 



CLUSTERED BEAKED-RUSH. (R. glomerata.) 

 b Spikelets mostly terminal, sometimes in i or 2 axillary 

 clusters; stems very slender 



WHITE BEAKED-RUSH. (R. alba.) 



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