162 FLORA. 



often compound; primary rays 1-6 cm. long; spikelets numerous, usually densely 

 clustered, linear, acute, 8-20 cm. long, 2-3 mm. wide, flat, many-flowered, spread- 

 ing; scales oblong, obtuse, thin, dull, yellowish-brown; stamens 3; style 2-cleft, 

 little exserted; achene obovate, lenticular, black, mucronate, not shining, nearly 

 as long as the scales and often persistent on the rachis after these have fallen 

 away. In wet or moist sandy soil, Va. to Fla. and La. Aug.-Oct. 



7. Cyperus inflexus Muhl. AWNED CYPERUS. (I. F. f. 549.) Annual; 

 culms slender or almost filiform, tufted, about equalled by the leaves. Leaves 

 2 mm. wide or less, those of the involucre 2-3, exceeding the umbel; umbel sessile, 

 capitate, or i-3-rayed; spikelets linear-oblong, 6-iO-flowered, 4-6 mm. long; scales 

 light brown, lanceolate, rather firm, strongly several-nerved, tapering into a long, 

 recurved awn, falling from the rachis at maturity; stamen i; style 3-cleft; rachis 

 winged, the wings persistent; achene 3-angled, brown, dull, narrowly obovoid or 

 oblong, obtuse, mucronulate. In wet, sandy soil, Vt. to the N. W. Terr, and Ore., 

 south to Fla., Tex., Cal. and Mex. Fragrant in drying. July-Sept. 



8. Cyperus compressus L. FLAT CYPERUS. (I. F. f. 550.) Annual; culms 

 slender, erect or reclining, smooth, 7-25 cm. long. Leaves light green, about 

 2 mm. wide, those of the involucre 2-3, the longer exceeding the spikelets; umbel 

 capitate or with 2-3 short rays; spikelets narrowly lanceolate, acute, 8-20 mm. 

 long, 3-4 mm. wide, very flat, many-flowered; scales light green with a yellow 

 band on each side, ovate, acuminate, firm, keeled, several-nerved, falling away 

 from the narrowly -winged rachis at maturity; stamens 3; style 3-cleft; achene 

 sharply 3-angled, obovoid, obtuse, dull, brown, about one-third as long as the 

 scale. In fields, Md. to Fla., west to Mo. and Tex. Also in trop. Amer. and the 

 Old World. Aug.-Oct. 



9. Cyperus Schweinitzii Torr. SCHWEINITZ'S CYPERUS. (I. F. f. 551.) 

 Perennial by the thickened corm-like bases of the culms; culms rather slender, 

 rough, at least above, 0.3-0.8 m. tall. Leaves 2-5 mm. wide, rough-margined, 

 those of the involucre 3-7, erect; umbel simple, 3-Q-rayed, the rays erect, some- 

 times 10 cm. long; spikelets flat, in rather loose ovoid spikes, which are linear- 

 oblong, 6-i2-flowered, 8-16 mm. long; scales convex, light green, ovate, acute or 

 acuminate, 9~i3-nerved, falling away from the rachis at maturity; stamens 3; 

 style 3-cleft; achene 3-angled, oblong, brown, acute at each end, nearly as long as 

 the scale. In sandy soil, especially along lakes and streams, W. N. Y. and S. 

 Out. to the N. W. Terr., Minn., Iowa and Kans. Aug. Oct. 



10. Cyperus pseudovegetus Steud. MARSH CYPERUS. (I. F. f. 552.) Per- 

 ennial by thickened tuber-like joints of the rootstocks, culm rather stout, 0.3-1.3 m. 

 high, often equalled by the leaves. Leaves 3-4 mm. wide, smooth, nodulose, 

 the midvein prominent; leaves of the involucre 4-6, spreading; umbel several- 

 rayed, compound; spikelets ovate, flat, many-flowered, light green, densely capi- 

 tate, 4-6 mm. long; scales keeled, conduplicate, i-nerved, curved, acute, longer 

 than the linear 3-angled slightly stalked achene; stamen i; style 3-cleft. In 

 marshes, Del. to Fla., west to Kans. and Tex. July-Sept. 



11. Cyperus acuminatus Torr. Hook. SHORT-POINTED CYPERUS. (I. F. f. 

 553.) Annual; culms very slender, tufted, 7-40 cm. tall. Leaves light green, 

 usually less than 2 mm. wide, those of the involucre much elongated; umbel 1-4- 

 rayed, simple; rays short; spikelets flat, ovate-oblong, obtuse, 4-8 mm. long, many- 

 flowered, densely capitate; scales oblong, pale-green, 3-nerved, coarsely cellular, 

 conduplicate, with a short sharp more or less recurved tip ; stamen i ; style 

 3-cleft; achene sharply 3-angled, gray, oblong, narrowed at each end, about one -half 

 as long as the scale. In moist soil, 111. to La., west to Iowa. Kans., Ore., Tex., 

 and Cal. July-Oct. 



12. Cyperus fuscus L. BROWN CYPERUS. (I. F. f. 554.) Annual; culms 

 tufted, 15-40 cm. high, longer than or equalled by the leaves. Leaves rather dark 

 green, about 2 mm. wide, those of the involucre 46; umbel several -rayed; spike- 

 lets linear, 4-14 mm. long, less than 2 mm. wide, many-flowered, acute; scales 

 ovate, subacute, becoming dark brown, faintly about 3-nerved, separating from the 

 narrowly winged rachis as they mature; stamens 2 or 3; style 3-cleft; achene 

 3-angled, oblong, pointed at each end, nearly as long as the scale. Revere Beach, 

 Mass., and New London, Conn. Adventive or fugitive from Europe. Also m 

 ballast about the eastern seaports. July-Sept. 



