CYPERACEAE. 55 



narrowed into a rough beak more than half the length of the body, the teeth 

 and suture on inner face conspicuous. Our plant is C. Leersii angustata 

 (Carey) Mackenzie. — N. Occasional, in boggy meadows. — Sandstones and 

 shales. — Sum. 



14. O. incomperta Bickn. Deep-green: leaves usually exceeding culm; blades 

 1-2 mm. wide : culms slender, 2-3 dm. tall, rough at least above : spikes 3-6, 

 subglobose, 5-15-flowered, approximate or a little separate, about 5 mm. thick: 

 staminate flowers at base of terminal spike conspicuous: scales ovate, acute or 

 short-acuminate, much shorter and narrower than perigynia: perigynia deep- 

 green, 2.5-3 mm. long, plano-convex, many-nerved on inner face, widely spread- 

 ing or reflexed, the body broadly ovate or ovate-orbicular, abruptly contracted 

 into a rough beak, half the length of the body, the teeth and suture on inner 

 face conspicuous. — Occasional, in swamps and swampy woods. — Spr. 



15. C. scoparia Schk. Culms slender, 1.5-7.5 dm. tall, roughish above: leaf- 

 blades less than 3 mm. wide, those of sterile shoots few, ascending: spikes 3-10, 

 oblong, narrowed at both ends, bright-brown, 6-16 mm. long, aggregated into 

 an ovoid head or separated : scales thin, brown, acute or acuminate, shorter than 

 the perigynia: perigynia lanceolate, 4-6.5 mm. long, rather less than 2 mm. 

 wide, narrowly wing-margined, several-nerved on both faces, each tapering into 

 a serrulate 2-toothed beak. — Rather common, in moist soil. — Sum. 



16. 0. tribiiloides Wahl. Culms 2-9 dm. tall, roughish above: leaf -blades flat, 

 3-8 mm. wide, those of sterile shoots numerous, widely spreading: lower bract 

 bristle-form : spikes 6-20, obovoid or top-shaped, varying to suborbicular, blunt, 

 7—12 mm. long: scales lanceolate, whitish, acute, about J as long as the peri- 

 gynia: perigynia lanceolate, greenish-brown, flat, 3.5—5 mm. long, 1.5 mm. wide, 

 appressed or ascending, several-nerved on both faces, each with a sharply 2- 

 toothed rough wing-margined beak. — Rather common, in moist soil. — Sum. 



17. C. cristatella Britton. Culms 2.5-7.5 dm. tall, roughish above, overtopping 

 the leaves: leaf -blades flat, 3-7 mm. wide, those of sterile shoots numerous, 

 widely spreading: spikes 6-15, globose or subglobose, greenish or brownish, 

 4-S mm. long, aggregated into a cylindric or oblong head: scales lanceolate, 

 whitish, much shorter than the perigynia: perigynia lanceolate or ovate-lanceo- 

 late, 3-4 mm. long, squarrose at maturity, narrowly wing-margined, several- 

 nerved on both faces, each tapering into a serrulate 2-toothed beak. — Occa- 

 sional, especially in the Susquehanna valley. — Sum. 



18. C. straminea Willd. Cxdms slender, 3-7.5 dm. tall, roughish above, the 

 top commonly nodding: leaves shorter than the culm; blades 2 mm. wide or less, 

 long-pointed: bracts short or the lower bristle-form and exceeding its spike: 

 spikes 3-&, slightly longer than thick, narrowed at the base, slightly obovoid, 

 4—5 mm. thick: scales lanceolate, acute, shorter and narrower than the peri- 

 gynia : perigynia ascending or spreading, ovate, 3-4 mm. long, green, strongly 

 several-nerved on the outer face, fewer-nerved or nerveless, on the inner, 

 wing-margined, the tapering rough 2-toothed beak shorter than the body. — 

 Rather rare, in meadows. — Sum. 



19. C. festucacea Schk. Culms slender or stoutish, 3-12 dm. tall, erect, rough- 

 ened beneath head: leaves shorter than the culm; blades 2-4 mm. wide: bracts 

 short or wanting: spikes 3-10, in a stitf head, approximate or separate, 7-15 

 mm. long, 4-9 mm. wide, rounded or narrowed at base: scales ovate-lanceolate, 

 obtuse or acutish, shorter and narrower than the perigynia: perigynia spreading 

 or ascending, orbicular to broadly ovate, 4-4.5 mm. long, 2.5-3.5 mm. wide, 

 thickish, sirongly nerved on outer face, nerveless or nearly so on inner face, 

 green, strongly wing-margined, the rough bidentate beak one-third the length 

 of the body. — Occasional, in low woods and swamps. — Sum. 



20. C. hormathodes Fernald. Culms very slender, 3-9 dm. tall, the summit 

 often nodding, usually strongly roughened above: leaves shorter than culm; 



