518 CYrKu.vci.,1:. (skdck ia.mii.y.) 



none. — Mar^rins of ponds and stronms, West Florida. June -Aug. ® — 

 Culms 3'-5' lii;.'li. Spikes 1" -2" lung, the lower scale.s deciduous as new 

 flowers are developed. Nut blaek, smooth and shining. 



■*- ■*- Culms terete or compressed, more or less spongy. 



10. E. capitata, R. Brown. Khizoma slender, eroeping; culms com- 

 pres.sed; sjiikes short, ovate, 12 - 16-flowered ; scales nienihranaccous, whitish, 

 oMoug, obtuse, deciduous ; nut black and shining, broadly obovatc, biconvex, 

 tipped with the short conical tubercle ; bristles 6, as long as the nut. — Springy 

 or miry places, Florida, Georgia, and westward. June -Sept. IJ. — Culms 

 l'-4'high. Spikes I "-a" long. Scales often brown when young. Nut very 

 small. 



20. E. olivacea, Torr. Cnlms compressed, furrowed, diffuse ; spikes 

 ovate, acutish, many-Howered ; scales ovate, ol)tuse, thin, pur|)lish on the sides, 

 green on the keel, the margins white ; nut obovatc, dull, dark olive ; tui)ercle 

 distinct, conical-beaked; bristles 6-8, about half as long as the nut. — "Wet 

 sandy places, North Carolina, and northward. Aug. aud Sept. — Culms 2' -5' 

 long. Spikes 3" long, 20-30-flowcred. 



21. E. palustris, R Brown, llhizoma creeping; culms slender, terete, 

 striate; spikes obloug-laiiceolate, mostly acute, many-flowered; scales oblong, 

 membranaceous, brown on the sides, at length whitish, the upper ones acute ; 

 nut dull yellow, obovate, tumid, minutely dotted; tubercle short, triangular- 

 ovate, compressed; bristles 4, slender, commonly as long as the nut. (Scirpus 

 palustris, L.) — Marshes and wet places, Florida, and northward. June -Sept. 

 y. — Khizoma black. Culms l°-3° l6ng. Spikes 3" -5" long. 



22. E. obtusa, Schultes. Culms tufted, terete, thick and spongy ; spikes 

 ovate or oblong, obtuse, many-flowered; scales thin, oblong, obtuse, commonly 

 brown on the sides, green on the keel, with broad and white margins; style 

 2-3-cleft; nut (light brown) obovate, lenticular, smooth and shining, scarcely 

 wider than the short com])ressed acute tubercle ; bristles 6, rigid, twice the length 

 of the nut. (Scirpus capitatus. Ell.) — Muddy margins of ponds and streams, 

 Florida, and northward. Common. June -Sept. — Culms C- 18' high. Sjnkes 

 2" - 4" long. 



^ 2. CH.(ETOCYPERUS. Spikes Jew-Jlowered, compressed: scales membranaceous, 

 imbricated in 2-3 rows: style 3-cleft. Culms capillary. 



23. E. acicularis, R. Br. Culms (2' -12' high) angled; spikes ovate, 

 5-C-flowcred, acute; scales oblong, with reddish sides, nut oblong, white, 

 nearly terete, longitudinally ribbed and pitted, pointed with the conical or de- 

 pressed tubercle ; bristles 3-4, shorter than the nut, sometmics wanting. (Scir- 

 l)us trichodes, Muhl.) — Margins of ponds, Florida, and northward. June- 

 Sept. 



24. E. pygmsea, Torr. Culms short (r-2' high), grooved on one side; 

 spikes ovate, 3- G-flowered ; scales whitish, ovate ; nut ovate, pale, prominently 

 3-angled, smooth and shining, narrowed above into the minute tubercle; bristles 

 6, longer than the nut, sometimes wanting. (Scirpus capillaceus, Ell.} — Muddy 



