SIRRING FLORA OF MANHATTAN. 9 



H. nodosum, L. Awn about as long as glume [i cm.) erect. Stem 

 low, 1-5 dm. Spike sometimes enclosed in upper sheath, breaking up at 

 maturity into joints. Sterile soil, common. 



ELYMUS, L. 



Much as in Hordeum but spikelets all perfect and usually more than 

 1-flovvered. 



E. C(mt(densts vav. (jlaucifoliiis, ( Willd.) Torr. Spike large and thick. 

 Empty glumes strongly nerved, awned. Flowering glumes with long 

 spreading, capillary awns. Large grass with rough leaves. Low land, 

 common. 



2. CYPERACEAE. 



Proper perianth none, sometimes represented by bristles or scales. 

 Stamens usually 3. Ovary one, superior, 1-celled, 1-ovuled. Style 2-3- 

 cleft Fruit an achene. Flowers in the axils of bracts; no bract 

 between tlie flower and the axis. Grass-like plants with 3-ranked 

 leaves and closed sheaths. 



ELEOCIIARIS, R. Rr. 



Flowers perfect, in a single spike terminating the naked stem. 

 Ovary surrounded by several bristles. Style thickened at the base form- 

 ing a tubercle on the achene. 



E. palustris, (L ) R. & S Stems cylindrical, striate, l-o dm. high. 

 In mud or shallow water, common. 



SCIRPUS, L 



Resembling Eleocharift but style not thickened. In our species the 

 1-several spikelets are at the apex of the stem, with an involucral leaf 

 which may appear as a continuation of the stem. 



»S. Americanus, Pers. Spikelets 1-several, sessile, involucral leaf 

 much longer than the cluster. Stems triangular. Wet places. 



;S'. Incustris, L Spikelets panicled, the involucral leaf shorter than 

 the cluster. Stems cylindrical, tall. Wet places. 



CAREX, L 



Flowers monoecious, the two kinds in the same or different spikes. 

 Achene enclosed in a sac (perigynium) Stems usually triangular. 



'i 1. Staminate flower.s in one or more terminal spikes; the pistillate 

 spikes below, usually peduncled. Achene triangular. 



C. hystricina, Muhl Pistillate spikes 1-3, drooping on slender stalks, 

 oblong and densely flowered Perigynium smooth, strongly nerved, 

 somewhat inflated, narrowed into a slender beak as long as the body. 

 Swampy ground. 



C. Miformis. var. lanngbiosa, {M.[chx..) B. S. P. Pistillate spikes 1-3, 

 erect and nearly sessile. Perigynium short beaked, deeply 2-toothed, 

 densely pubescent. Low prairie. 



C. trichocarpa, Muhl. Staminate spikes several. Pistillate spikes 

 usually 2 3, upper erect, lowermost long stalked and spreading. Peri- 

 gynium smooth, nerved, the short beak extending into 2 long, bristle- 

 like teeth. Coarse plants growing in marshes. 



C. .s/rjr/a. Lam. Spikes several; pistillate slender and compactly 



