54 CYPEKACEAE. 



mainly brown, strongly separate and forming a flexuous head, 4-8 dm. long: 

 bracts small or obsolete: scales ovate, thin, acute or short-awned: perigynia 

 ovoid, light-brown, 2.5-3 mm. long, hard, plump, nearly flat on inner face, 

 usually exceeded by the scales, the beak rather shorter than the body. M. 

 Bare, in the Dillerville swamp. Limestones. Sum. 



8. C. stipata Muhl. Leaves green; blades flat, 4-8 mm. wide; sheaths strongly 

 septate, the opaque part thin, strongly transeversely rugulose, easily breaking: 

 culms stout at base, sharply 3-angled, 4-12 dm. tall: bracts bristle-form or 

 wanting: spikes numerous, yellowish-brown, in a terminal oblong cluster 3-10 

 cm. long, the staminate flowers few, always terminal : scales ovate or lanceolate, 

 acuminate, much shorter than the perigynia: perigynia lanceolate, 4-5 mm. 

 long, each tapering into a rough flattened 2-toothed beak 1-2 times as long as 

 the body. Common, in meadows and swamps. Sum. 



9. C. laevi-vaginata (Kiiken.) Mackenzie. Leaves light-green; blades flat, 

 3-6 mm. wide; sheaths sparingly septate, the opaque part thickened at the 

 mouth, not transversely rugulose, not easily breaking: culms little thickened at 

 the base, sharply 3-angled, 4-8 dm. tall: bracts inconspicuous: spikes numerous, 

 yellowish-green, in a terminal linear-oblong or oblong cluster, 2.5-6 cm. long, 

 the staminate flowers few, always terminal: scales ovate or lanceolate, acumi- 

 nate, much shorter than the perigynia: perigynia lanceolate, 4.55 mm. long, 

 each tapering into a rough flattened 2-toothed beak longer than the body. M. 

 Frequent, in meadows and swamps. Limestones. Sum. 



10. C. bromoides Schk. Leaves soft; blades 2 mm. wide or less, flat: culms 

 slender, very rough above, 2-6 dm. long: bracts subulate or bristle-form, the 

 lowest commonly elongated: spikes 37, narrowly oblong-cylindric, 7-18 mm. 

 long, erect or ascending, mostly close together, the staminate flowers either 

 basal, basal and terminal, or both: scales oblong-lanceolate, green, brownish 

 tinged, obtusish to acuminate, shorter than the perigynia: perigynia linear- 

 lanceolate, pale, little margined above, strongly several-nerved, 4-5.5 mm. long, 

 the inner face flat, the tapering rough 2-toothed beak at least i as long as the 

 body. M. Rare, in wet woods. Limestones. Sum. 



11. C. sterilis Willd. Leaves shorter than the culm; blades 1-2 mm. wide: 

 culms slender, 2-4.5 dm. tall, rough, at least above: spikes 3-8, subglobose or 

 short-oblong, about 5 mm. thick: staminate flowers usually numerous at the 

 bottom of the upper spike, or whole spikes staminate, or plants occasionally 

 quite dioecious: scales ovate, shorter than the perigynia, obtuse or acutish: 

 perigynia ovate, compressed, appressed or ascending, or in extreme age spread- 

 ing, little exceeding scales, rough edged above, the teeth short and suture on 

 inner face little developed, 2.5 mm. long, 1 mm. wide, several-nerved on outer 

 face, obsoletely nerved on inner face, each tapering into a sharp-edged 2-toothed 

 rough beak not 1 as long as the body. M. Bare, in swamps. Limestones. 

 Early sum. 



12. C. interior Bailey. Similar to C. Leersii in habit. Leaves shorter than the 

 culm; blades 1-2 mm. wide: culms slender, wiry, 2-6 dm. tall: spikes 2-4, 

 nearly globular, 4 mm. in diameter: scales ovate, obtuse to acutish, conspicu- 

 ously shorter than the perigynia: perigynia soon spreading, ovate, 2.25 mm. 

 long or less, faintly few-nerved on the outer face, nearly nerveless on the inner, 

 plump, each abruptly contracted into a roughened 2-toothed beak ^ to i as long 

 as the very sparingly serrulate body, the teeth very short and suture on inner 

 face not conspicuous. M. Bather rare, in wet places. Limestones. Sum. 



13. C. Leersii Willd. Light-green: leaves usually exceeding culm; blades 0.5- 

 1 mm. wide: culms very slender, 1.5-3 dm. tall, smooth or very nearly so 

 throughout: spikes 2-5, 2-8-flowered, more or less strongly separate: staminate 

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

 cuspidate, much shorter than perigynia: perigynia light-green, 3-3.5 mm. long, 

 plano-convex, obscurely nerved on inner face, widely spreading, tapering or 



