286 CYPERACEAE. 



J J Teeth of the perigynium-beak short or almost wanting (long in no. 17) nos. 11-24. VESICARIAE. 



Spikes small, i' long or less, oblong or subglobose; stigmas often 2. 

 Spikes green or greenish yellow. 



Leaves involute ; perigynia ovoid ; pistillate spikes few-several-flowered. 1 1 . C. oligosperm 

 Leaves flat; perigynia oblong-elliptic; pistillate spikes many-flowered. 12. C. Raeana. 

 Spikes dark brown or purple; arctic species. 

 Leaves flat. 



Perigynia little inflated, papery. 



Beak of perigynium nearly or quite entire. 13. C. mi liar is. 



Beak of perigynium sharply and minutely 2-toothed. 14. C. saxatilis. 



Perigynia much inflated, very fragile. 15. C. membranopacta 



Leaves involute when dry. 16. C. ambusta. 



Spikes large, i'-6' long, cylindric or oblong-cylindric; stigmas 3. 



Scales acute, acuminate or smooth-awned, or the lower slightly roughened. 

 Perigynia ascending or spreading, not reflexed. 



Spikes narrowly cylindric, i -6' long, 3" -4" thick. 



Leaves 2"-6" wide; culm stout. 17. C. utriculala. 



Leaves i"-2$4" wide; culm slender. 18. C. monile. 



Spikes cylindric or oblong cylindric, i'-2 ( long, 6" thick. 



Scales smooth-awned. 19. C. Tuckermani. 



Scales acute, acuminate or the upper obtuse. 20. C. bullata. 



Perigynia, at least the lower ones, reflexed when mature. 



Spikes all clustered at the summit or the lower i or 2 separated; perigynia all reflexed 



when old. 21. C. retrorsa. 



Spikes scattered; only the lower perigynia reflexed. 22. C. Hartii. 



Scales tapering into rough awns, or subulate and scabrous. 



Spikes cylindric, about 6" thick; perigynia tapering into the beak. 23. C. lurida. 

 Spikes narrowly cylindric, 3" -4" thick; perigynia abruptly narrowed into the beak. 



24. C. Baileyi. 



ft Teeth of the perigynium-beak stiff; setaceous or awned. Nos. 25-28. PSEUDOCYPERAF.. 



Spikes all erect or ascending. 25. C. Schweinitzii. 



Spikes, at least the lower ones, slender-stalked and drooping. 



Pistillate spikes oblong-cylindric, %'-3 long; perigynia ascending. 26. C. hystricina. 

 Pistillate spikes narrowly cylindric, i'~2 I A' long; perigynia reflexed. 



Teeth of the beak erect or little spreading. 27. C. Pseudo-cypenis. 



Teeth of the beak recurved-spreading. 28. C. comosa. 



** Perigynia obovoid, very abruptly contracted into the beak; spikes exceedingly dense. Nos. 29- 



31 . SQUARROSAE. 



Scales linear-subulate, longer than the perigynia. 29. C. Frankii. 



Scales lanceolate, about one -half as long as the perigynia. 



Spikes 1-3, subglobose or oval, staminate below; achene linear-oblong. 30. C. squarrosa. 



Spikes 2-6, oblong-cylindric, usually staminate at both ends; achene ovoid. 31. C. typliinoides. 



(b) Perigynia firm, hard or leathery. Nos. 32-35. PALUDOSAE. 



Leaves bright green, not glaucous; teeth of the perigynium-beak slender, conspicuous. 



Scales lanceolate, acute or acuminate; leaves glabrous. 32. C. trichocarpa. 



Scales ovate-lanceolate, rough -awned; leaves often pubescent. 33. C. aristata. 



Leave_s pale green, glaucous: teeth of the perigynium-beak short. 



Pistillate spikes about 4" thick, teeth of the perigynium-beak manifest. 34. C. riparia. 



Pistillate spikes about 2" thick; teeth of the perigynium-beak minute. 35. C. acutiformis. 



B. PERIGYNIA SHORT-BEAKKD OR BEAKLESS, LITTLE OR NOT AT ALL INFLATED, '/>>'" -2 Ji" 



LONG, THE BEAK COMMONLY NOT MORE THAN ONE-HALF AS LONG AS THE BODY ( LONG-BK.VKKD 

 IN NOS. 43, 82, 83, 96); SPIKES SMALL, AND OBLONG OR GLOBOSE; OR ELONGATED, LINEAR OR 

 NARROWLY CYLINDRIC. NOS. 36-142. 



(a) Spikes 2 or more, the slam inate one always uppermost, sometimes partly pistillate. (No. 140 

 may be looked for here). Nos. 36-132. 



1. Pistillate spike or spikes many-flowered, mostly i' long or more (or shorter in nos. 44. 4>. 

 61, 63-65, 73, 75, 76, 85, 89-92), linear, narrowly cylindric or oblong. Nos. 36-92. 



* Perigynia with a straight short beak (long-beaked in no. 43 ; nearly beakless in no. 36), firm or leathery 

 in texture ; pistillate spikes erect (or nodding in no. 37); stigmas 3. Nos. 36-43. 



Uppermost spike staminate from the base to about the middle. SHORTIANAE. 36. C. Shortiana. 

 I'pper 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 m no. 39), the beak sharply 2-toithed. HIRTAK. 

 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. ll'alteriana. 

 Scales equalling or but slightly shorter than the perigynia; northern spe^ 



Leaves 2"-3^" wide; pengynia i^" thick, the nerves prominent, 



40. C. IfOHffll 



Leaves i"-2" wide; perigynia i" thick, the nerves obscured by the dense 



pubescence. 41. C. lanuginosa. 



leaves strongly involute, i" wide or less. 42. C. filiformis, 



leaves or their sheaths pubescent: introduced species; beak long. 43. C. liii ta. 





