CYPERACE^E. (SEDGE FAMILY.) 579 



3. S. planifdlius, Muhl. Culms triangular, leafy at base ; leaves linear, 

 flat, as long as the culm, and like it rough-edged ; involucral bract a bristle- 

 tipped scale usually overtopping the ovate or oblong chestnut-colored spikelet, 

 the green midrib of the scales extended into sharp points ; bristles upwardly 

 hairy, as long as the pointless achene. Dry or moist ground, N. Eng. to 

 Del., west to western N. Y. and Penn. ; W. Mo (B. F. Bush.). 



- -i- One-leaved involucre more conspicuous, and as if continuing the culm. 



4. S. subterminalis, Torr. Aquatic; culms (1-3 long, thickish-fili 

 form) p rtly and the shorter filiform leaves wholly submersed, cellular ; the 

 filiform green bract 6- 12" long, much surpassing the oblong spikelet; scales 

 somewhat pointed; bristles 6, bearded downward, rather shorter than the ab- 

 ruptly-pointed achene. Slow streams and ponds, N. Eng. to N. J., west to 

 Mich, and N. Ind. Var. TERRESTRIS, Paine; less tall, with firmer stem and 

 leaves, and fruiting spike more turgid. Growing chiefly emersed ; Herkimer 

 Co., N. Y. 



* * Spikelets clustered (rarely only one), appearing lateral, the one-leaved invo- 

 lucre resembling and seeming to be a continuation of the naked culm. 



-*- Culm sharply triangular, stout, chiefly from running rootstocks ; spikelets many- 

 flowered, rusty brown, closely sessile in one cluster ; sheaths at base more or 

 less leaf-bearing. 



5. S. plingens, Vahl. Running rootstocks long and stout; culm sharply 

 3-angled throughout (1-4 high) with concave sides; leaves 1 - 3, elongated 

 (4- 10' long), keeled and channelled; spikelets 1 - 6, capitate, ovoid, usually 

 long, overtopped by the pointed involucral leaf ; scales ovate, sparingly ciliate, 

 2-cleft at the apex and awn-pointed from between the acute lobes ; anthers 

 tipped with an awl-shaped minutely fringed appendage ; style 2-cleft (rarely 

 3-cleft) ; bristles 2-6, shorter than the obovate plano-convex and mucronate 

 smooth achene. Borders of salt and fresh ponds and streams, throughout 

 N. Am. (Eu., S. Am.) 



6. S. Torr6yi, Olney. Rootstocks slender if any (so that the plant is 

 readily pulled up from the mud); culm 3-angled, with concave sides, rather 

 slender (2-4 high), leafy at base; leaves 2 or 3, more than half the length oj 

 the culm, triangular-channelled, slender ; spikelets 1-4, oblong or spindle-shaped, 

 acute, distinct, pale chestnut-color, long overtopped by the slender erect invo- 

 lucral leaf ; scales ovate, smooth, entire, barely mucronate ; style 3-cleft ; bris- 

 tles longer than the unequally triangular-obovate very smooth long-pointed achene. 

 Borders of ponds, brackish and fresh, N. Eng. to Penn., Mich., and Minn. 



7. S. Oln6yi, Gray. Culm 3-wing -angled, with deeply excavated sides , 

 stout (2-7 high), the upper sheath bearing a short triangular leaf or none; 

 spikelets 6-12, closely capitate, ovoid, obtuse, overtopped by the short invo- 

 lucral leaf; scales orbicular, smooth, the inconspicuous mucronate point 

 shorter than the scarious apex ; anthers with a very short and blunt minutely 

 bearded tip ; style 2-cleft ; bristles 6, scarcely equalling the narrowly obovate 

 plano-convex and mucronate achene. Salt marshes, S. New Eng. to Fla., 

 west to the Pacific. 



S. MUCRONA.TUS, L. Resembling the last, 1-3 high ; spikelets numerous 

 in a dense cluster, oblong-ovate, 6 - S" long or less ; scales ovate, mucrouate. 



