EEPOKT OF THE STATE BOTANIST. 37 



prolongation, or the lowest setaceous or leaf-like; perigynia 

 ovate, nerved at the base, minutely punctate, whitish, tapering 

 into a short bifid or entire beak, divergent at maturity, a little 

 longer than the ovate, acute or obtuse scale ; achenium elliptical. 



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



Readily determined by its silvery spikes and glaucous-green foli- 

 age. Small, slender forms with fewer flowered spikelets, but 

 glaucous foliage approach the following variety. A form occurs 

 in Suffolk county in which the terminal spikelet is wholly stami- 

 nate or bears but few perigynia. 



Yar. vulgaris Bailey. Differs from the type in its more slender, 

 erect, or diffuse stems ; its narrower, green, not glaucous, leaves ; 

 its fewer and smaller spikelets, with fewer flowers, and in its 

 green, horizontally-spreading perigynia with more pronounced 

 beaks and shorter scales. 



Yar. alpicola ^Yahl. Stems G'-15' high, firm, erect or spreading; 

 leaves green, 1" wide; spikelets 3-5, globular, 6-15 flowered, the 

 lowest sometimes with a filiform bract 2'-2|-' long, sometimes the 

 next above with a bristle-shaped bract ^' or more in length ; 

 perigynia green with brown spots or tawny ; otherwise as in the 

 preceding. A lowland form has capillary stems 15'-20' high, 

 leaves ^" wide or less ; perigynia green slightly dashed with 

 brown. 



Spikelets o-S (single in 18) ovoid or oblong, approximate above, 

 interrupted below, or all scattered ; perigynia slightly concave, 

 rough or smooth-margined, nerved or nerveless, usually strongly 

 rcflexed at maturity ; bracts bristle-form or rarely the lowest 

 leaf-like. Plants rather rigid, green, often becoming yellowish 

 with age. In all the species of this group the terminal spikelet 

 appears to bo stalked, the lower part being much contracted and 

 clothed with the scales of the staminate flowers. 



Perigynia ovate, small 1 



Perigynia ovate or ovate-laoceolate, large 2 



1 Spikelets scattered; perigynia with a short smooth beak. . . seorsa. 

 1 Spikelets contiguous or approximate, perigynia rough- 

 beaked interior. 



2 Spikelet single, sometimes wholly fertile or wholly sterile, exilis. 



2 Spikelets approximate or scattered sterilis. 



