C YPERA CEA E. 1 97 



stalked, 2-10 cm. long, perigynia ascending, conic, glabrous, many-ribbed, 

 8-12 mm. long, tapering into the conspicuously 2-toothed beak, the teeth divergent; 

 scales oblong-lanceolate, rough-awned, one-half to two-thirds as long as the peri- 

 gynia. In bogs, Out. to the N. \Y. Terr., N. Y., Iowa, Utah and Ore. June-Aug. 



34. Carex riparia Curtis. River-bank Sedge. (I. F. f. 704.) Glabrous, 

 pale green; culms smooth, or roughish above, 0.5-1 m. tall. Leaves elongated, 

 6-12 mm. wide, about equalling the culm; staminate spikes 1-5; pistillate spikes 

 2-5. cylindric, 3-10 cm. long, about 8 mm. in diameter, the upper erect, sessile or 

 nearly so, the lower stalked; perigynia narrowly ovoid, firm, scarcely inflated, 

 ascending, tapering into a short 2-toothed beak, the teeth divergent; scales lanceo- 

 late or oblanceolate, long-aristate or acute, the lower longer, the upper equalling 

 or shorter than the perigynia. In swamps, Newf. to James' Bay and Manitoba, 

 south to Fla., La., Tex. and Idaho. Also in Europe. May-Aug. 



35. Carex acutiformis Ehrh. Swamp Sedge. (I. F. f. 705.) Culms stout, 

 sharp-angled, 0.5-0.9 m. tall, often rough above. Leaves 5-12 mm. wide, flat, pale 

 green; lower bracts similar to the leaves, the upper short and narrow; staminate 

 spikes 1-3, stalked; pistillate spikes 3-5, linear-cylindric, 3-8 cm. long, 4-5 mm. 

 thick, the upper sessile or nearly so and erect, the others slender-stalked, spread- 

 ing or drooping; perigynia ovoid, 3 mm. long, not inflated, many-nerved, tapering 

 into a short and minutely 2-toothed beak; scales awn-tipped, longer than the peri- 

 gynia or the upper equalling them. In swamps and wet meadows, E. Mass. Nat- 

 uralized from Europe. June-Aug. 



Uppermost spike staminate from the base to about the middle. Shortianae. 



36. C. Shorttana. 

 Upper one or more spikes entirely staminate, or occasionally pistillate at the base. 



Perigynia papillose; beak very short, nearly or quite entire. Anomalae. 



37. C. scabrata. 

 Perigynia pubescent (sometimes glabrous in no. 39), the beak sharply 2-toothed. 



Hirtae. 

 Staminate spike or spikes sessile or nearly so. 38. C. vestita. 



Staminate spike or spikes distinctly stalked. 

 Leaves glabrous ; native species. 



Leaves flat or their margins slightly revolute. 



Scales only half as long as the perigynia; southern coast species. 



39. C. Walteriana. 

 Scales equalling or but slightly shorter than the perigynia; northern 

 species. 

 Leaves 4-7 mm. wide; perigynia 3 mm. thick, the nerves 

 prominent. 40. C. Houghtonii. 



Leaves 2-4 mm. wide; perigynia 2 mm. thick, the nerves ob- 

 scured by the dense pubescence. 41. C. lanuginosa. 

 Leaves strongly involute, 2 mm. wide or less. 42. C.fili/ormis. 

 Leaves or their sheaths pubescent; introduced species; beak long. 



43. C. hirta. 



36. Carex Shortiana Dewey. Short's Sedge. (I. F. f. 706.) Glabrous; 

 culms slender, rough above, 0.3-1 m. tall, usually overtopped by the upper leaves. 

 Leaves elongated, roughish, 4-5 mm. wide; bracts short, narrow, rarely much 

 exceeding the spikes; spikes 3-7, linear-cylindric, densely many-flowered, J-3 

 cm. long, 3-4 mm. in diameter, erect, the lower stalked; perigynia dark brown, 

 compressed. 2-edged, orbicular or obovate, nerveless, abruptly minutely beaked, 

 equalling or shorter than the scales, which are hyaline, scarious-margined, ovate 

 or oblong- lanceolate, persistent; orifice of the perigynium entire or very nearly so; 

 stigmas 3. In moist meadows and thickets, Penn. to Va. and Tenn., west to Iowa 

 and the Ind. Terr. May-July. 



37. Carex scabrata Schwein. Rough Sedge. (I. F. f. 707.) Glabrous; 

 culms rough above, leafy, 0.3-0.9 m. long. Leaves rough, much elongated, 5-7 mm. 

 wide, the bracts similar but narrower ; staminate spike short-stalked ; pistillate 

 spikes 3-6. erect, the upper short-stalked, the lower sometimes spreading or droop- 

 ing, all linear-cylindric, densely many-flowered, 2-5 cm. long, 5-8 mm. in diameter; 

 perigynia greenish brown, ovoid, somewhat inflated, strongly nerved, papillose, 

 tipped with a short minutely 2-toothed or entire beak ; scales lanceolate, acute or 



