286 CYPERACEAE. 
tt Teeth of the perigynium-beak short or almost wanting (long in no. 17) nos. 11-24. VESICARIAE, 
Spikes small, 1’ long or less, oblong or subglobose; stigmas often 2. 
Spikes green or greenish yellow. 
Leaves involute; perigynia ovoid; pistillate spikes few-several-flowered. 11. C. oligosperma. 
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. miliaris. 
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, 1’-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, 1'-6' long, 3'’-4'' thick. 
Leaves 2''-6'’ wide; culm stout. 17. C. utriculata. 
Leaves 1''-2's"' wide; culm slender. 18. C. montle. 
Spikes cylindric or oblong cylindric, 1'-2' long, 6"’ thick. 
Scales smooth-awned. 19. C. Tuckermant. 
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 1 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. Batley. 
++ Teeth of the perigynium-beak stiff; setaceous or awned. Nos. 25-28. PSEUDOCYPERAE. 
Spikes all erect or ascending. 25. C. Schweinitzit. 
Spikes, at least the lower ones, slender-stalked and drooping. 
Pistillate spikes oblong-cylindric, 44’-2' long; perigynia ascending. 26. C. hystricina. 
Pistillate spikes narrowly cylindric, 1'-2's' long; perigynia reflexed. 
Teeth of the beak erect or little spreading. 27. C. Pseudo-cyperus. 
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. Frankti. 
Scales lanceolate, about one-half as long as the perigynia. 
Spikes 1-3, subglobose or oval, staminate below; achene linear-oblong. 30. _C. sguarrosa. 
Spikes 2-6, oblong-cylindric, usually staminate at both ends; achene ovoid. 31. C. (yphinoides. 
(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. 
Leaves 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-BEAKED OR BEAKLESS, LITTLE OR NOT AT ALL INFLATED, %s''-2'6"' 
LONG, THE BEAK COMMONLY NOT MORE THAN ONE-HALF AS LONG AS THE BODY (LONG-BEAKED 
IN NOS. 43, $2, 83, 96); SPIKES SMALL, AND OBLONG OR GLOBOSE; OR ELONGATED, LINEAR OR 
NARROWLY CYLINDRIC. NOS, 36-142. 
(a) Spikes 2 or more, the staminate one always uppermost, sometimes partly pistillate. (No. 140 
may be looked for here). Nos. 36-132. 
1. Pistillate spike or spikes many-flowered, mostly 1’ long or more (or shorter in nos. 44, 48, 53-55, 
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. 
Upper one or more spikes entirely staminate, or occasionally pistillate at the base. 
Perigynia papillose; beak very short, nearly or quite entire. ANOMALAR. 37. C. scabra/a. 
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 2''-314'' wide; perigynia 1's"' thick, the nerves prominent, 
40. C. Houghtonii. 
Leaves 1'’-2'' wide; perigynia 1’ thick, the nerves obscured by the dense 
pubescence. 41. C. lanuginosa. 
Leaves strongly involute, 1'’ wide or less. 42. C. filiformts. 
Leaves or their sheaths pubescent; introduced species; beak long, 43. C. Airta. 
