136 



NEW YORK STATE MCSEUM 



18. Carex exilis Dew. 



Stems l°-2° high, firm, erect or suberect, rough above ; leaves 

 involute, stiff, smooth, as long as the culm, or much shorter ; 

 spikes densely flowered, cylindrical or short oblong, contracted 

 at the base by the numerous scales of the staminate flowers, 

 sometimes wholly staminate or wholly pistillate, J'-l' long, light 

 brown ; perigynia ovate-lanceolate, few-nerved above, spreading, 

 tapering to a flat, rough-margined bidentate beak, a little longer 

 than the ovate-lanceolate scale. 



Cold swamps in the northern and eastern parts of the State ; 

 also on Long Island. Kare. June, July. 



This is a very distinct and easily recognized species. Some- 

 times an additional spike or two may develop at the base of the 

 usual one. 



19. Carex sterilis Willd. 



Stems 15-30' high, firm, erect, rough above ; leaves rough on 

 the edges, longer or shorter than the culm, broad, some- 

 times involute above ; spike i'-li' long, strict or flexuous, 

 yellowish-green or tawny ; spikelets 3-6, globose, i&"-3" in 

 length and thickness, IV -3" apart, or the upper 2 or 3 

 contiguous, the terminal contracted below and stalk-like 

 from the several staminate scales, or sometimes all staminate 

 or again each spikelet partly or wholly sterile ; bracts scale-like 

 or bristleform, the latter J'-l' in length ; perigynia variable, 

 ovate or evenly lanceolate, subcordate, one or both surfaces 

 nerved, contracted into a short or long, narrow, rough-mar- 

 gined, sharply toothed beak, widely divergent at maturity; 

 scale ovate, obtuse or acute, whitish or brown, shorter than the 

 perigynium ; achenium ovate. 



Culms with a single sterile spike frequently occur, and more 

 rarely with the lower half of the spike fertile. The perigynia 

 are mostly thin, but sometimes spongy at the base, strongly 

 divergent at maturity, their bristling tips occasionally bent or 

 deflexed. 



Swamps and wet places. Very common. May, June. 



Var. excelsior Bailey. Differs from the type in its taller, more 

 slender culms, mostly 2°-2-J° high ; its larger, greener, more 

 scattered spikelets, 3"-4:" long ; its larger perigynia prominently 

 nerved on both sides, and in its oblong- ovate, acute or pointed 

 scale. 



