39. Cyperus huarmensis (H.B.K.) M. C. Johnst. 



(Often loosely) tufted perennial from black knotty subrhizomatous bases; culms 

 1-4 dm. long, sub-basally 1.5-3 mm. thick, just beneath the inflorescence 0.7-1.3 

 mm. thick; leaves 2-4 mm. broad, firm, shorter than the culms; inflorescence 2-3 

 (-4) cm. long, of 3 to 6 essentially sessile (or occasionally 1 or 2 of them on 

 peduncles 1-2 cm. long) dense spikes 10-25 mm. long and 7-10 mm. thick, with 

 40 to 80 ascending spikelets; bracts 3 to 6, spreading, the longer ones 3 to 10 

 times as long as the inflorescence; spikelets 4-7 mm. long, about 1 mm. broad 

 and almost as thick, ochraceous gray-brown to tawny-gray, with 3 scales (usually 

 only the lowest one fertile and it slightly longer than the others), straight, the axis 

 at maturity detaching as a unit from the spike axis, the internodes of the fertile 

 side with 2 hyaline wings 1.5-2.2 mm. long and 0.6-0.8 mm. broad, clasping the 

 achene; fertile scale 3-4 mm. long, about 2 mm. broad, with about 9 nerves, 

 almost completely overlapping the higher scales; stamens 3; achene 1.5-2.1 mm. 

 long, 0.8-1 mm. thick, oblong-obovoid, trigonous, very dark-brown, substipitate, 

 apiculate. C. cayennensis (Lam.) Britt., non Link, C. flavus (Vahl) Nees, non 

 J. & C. Presl, Mariscus huarmensis H.B.K., C. obesus Liebm. 



Rare in s.e. Tex. (Aransas and San Patricio cos.) to Ariz. (Gila, Cochise, Pima 

 and Santa Cruz cos.), spring-fall; widespread in the warmer parts of Am. s. to 

 Arg. and n. to Ariz., N.M., Tex. and La. 



40. Cyperus Pringlei Britt. 



Perennial; culm erect, triangular, glabrous, to 6 dm. long, with swollen base 

 from short nodose rhizomes; leaf sheaths thin, subscarious, yellowish to reddish- 

 brown, to 12 cm. long; leaf blades flat, 3-8 mm. wide, glabrous or slightly scabrous 

 along the midrib and margins, to 3 dm. long; bracts 5 to 8, to 2 dm. long, sur- 

 passing the inflorescence; umbels simple or somewhat compound of 5 to 6 rays, 

 1-12 cm. long, spreading; spikes cylindric-oblong, rather loose, 7-10 mm. in 

 diameter, 1.5-3 cm. long; spikelets terete-oblong, 1 mm. in diameter or less, 3-5 

 mm. long, 3- to 5-flowered; scales pale yellow to light-brown, 2.2-2.5 mm. long, 

 1.5-2 mm. wide, distinctly 7 to 11 -nerved; rachilla scariously winged; stamens 3; 

 style deeply 3-cleft; achenes ellipsoid-oblong, trigonous, basal one-third of margin 

 enfolded by scarious rachilla wings, olive-brown, sublustrous, minutely punctate. 



Canyons, wet meadows and mt. slopes in Ariz. (Pima Co.), Aug.-Sept.; also 

 Chih. and Son. 



41. Cyperus hermaphroditus (Jacq.) Standi. 



Tufted perennial; culms very slightly thickened, 15-80 cm. long, sub-basally 

 1-3 mm. thick, just below the inflorescence 0.7-2 mm. thick; leaves 1-3 mm. 

 broad, the longer ones about as long as the culm; inflorescences 3-15 cm. long, 

 of 4 to 8 or more slender very unequal peduncles each with a lax spike 1-3 cm. 

 long and 1-2 cm. thick, of 8 to 30 or more divaricately spreading spikelets in 3 or 

 4 ranks, secondary peduncles absent; bracts 3 to 8, the longer ones far-surpassing 

 the inflorescence; spikelets linear, 5-1 1 mm. long, 0.5-1 mm. broad, more than 

 half as thick as broad, dull-brown, with 3 to 7 scales (the terminal one sterile, 

 tending to become involute and forming a short point), the axis at maturity detach- 

 ing as a unit from the spike axis, the internodes on their fertile side with 2 narrow 

 hyaline wings 1.3-2 mm. long and 0.3-0.5 mm. broad; scales 2.5-3.5 mm. long, 

 0.8-1.3 mm. broad, with about 9 nerves, overlapping, persistent; stamens 3; achene 

 1.6-1.8 (-2) mm. long, 0.6-0.8 mm. thick, trigonous, oblong to ellipsoid, yellow- 

 ish-brown to brown, substipitate, apiculate. Incl. var. angustior (Clarke) Kukenth., 

 C thyrsiflorus Schlecht. & Cham., C. dissitiflorus Torr. 



Rare in rich loam, shaded river woods, s.e. Tex. (Brazoria, Colorado, Harris 

 and Jackson cos.), and Ariz. (Pima Co.), summer; widespread in warmer parts of 

 Am., n. to Ala., La., Tex., Coah. and Ariz. 



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