26 CYPERACEAE. 



Stamen 1 : plants perennial. 4. C. surinununsis. 



Wings of the rachls manifest. 



Leaves reduced to pointed sheaths. 



In volucral bracts numerous : splkelets broad, 



1.5-2 mm. wide, reddish-brown. >:ltfrntfoUut. 



Involucral bracts mostly '2 : splkelets slender 



about 1 mm. wide, pale. :. C. Haspan. 



Leaves with elongate-linear blades. 7. C. rotundas. 



Rachls of the splkelets deciduous. 



Rachls breaking up Into 1-fruited joints: splkelets 



nearly terete. 8. C. spcciosua. 



Rachls deciduous above the lower pair of scales. 

 Achenes narrowly lliicur-uMong. 'J'.. 4 (ih. 



long as thick. 

 Splkelets distinctly flattened, several -m.-mv- 



flowered. '!m timluli i. 



Splkelets nearly terete to a little flattened. 



1 -few-flowered. 



Spikes obovold, the lower splkelets reflexed. 

 Splkelets with appressed scales : achenes 



about 2 mm. long. 1r. C.rctrorttu. 



Splkelets with lax scales : achenes about 



1.5 mm. long. 11. C. l l ,,ll<n;ll. 



Spikes cyllndrlc. IL-. r. !<, 



Achenes oblong to obovold, not more than twice as 



long as thick. 

 Splkelets with 1-4 achenes. 



Uachis wingless or narrowly winged. 



I'mbel simple: leaf-blades narrow. i .". <'. t< trujjunut. 



Umbel compound: leaf-blades broad. 14. C. ligtila>-i*. 



Rachls with broad membranous wings. i .V <'. liinatut. 



Splkelets with 5-10 achenes. 16. C. brunncua. 



1. 0. densus Link. Annual, 1-7 dm. tall: leaves generally L' or 4 ; l.lades 1-3 

 mm. wide, smooth: umbel capitate, or 2-4 rajs becoming 1-3 cm. long: 

 Bpikelets few, linear to linear-lanceolate, 5-8 mm. long, acutish: scales straw- 

 colored or yellowish-green, ovate, 2 mm. long: achenes oval or oval-obovoid, 1 

 mm. long, brown, dull, barely as long as the scale. [C, hclvus Liebm.] 

 Hammocks. (Cuba, Ant.) 



2. 0. paniculatus Rottb. Annual, 1-4 dm. tall: leaves often 3-6; blades 1-4 

 mm. wide, or sometimes narrower or even filiform, not firm: uml>rl with 3-8 

 rays 1-5 cm. long, or rarely nearly capitate: spikelets few, linear or I 

 lanceolate, 6-15 mm. long, acute: scales light chestnut-brown, oblong-lanceo- 

 late, 2-2.5 mm. long: achenes oblong, fully 1 mm. long, grayish, abruptly 

 apiculate, fully i as long as the scale Everglades. F. K. (Ber., Bah., Cuba, 

 Ant.) 



3. C. compressns L. Annual, with scapes 7-25 cm. long: leaves light-green; 

 blade* about 2 mm. wide: scapes smooth: umbel capitate or with 2-3 short 

 rmys: spikelets narrowly lanceolate, acute, 8-20 mm. long, 3-4 mm. \\i.U-. \>-ry 

 flat, many-flowered : scales light-green with a yellow band on each side, ovate, 

 acuminate: achenes obovoid, obtuse, dull-brown, about i as long as the scale. 

 Pinelands. F. K. (Bah., Cuba, Ant.) 



4. 0. rorinanmnsls Rottb. Perennial, 2-12 dm. tall : leaves overtopped by the 

 scape; blades mostly 1.5-4 mm. wide, usually rough along the margins: scapes 

 rough above: umbels mostly compound, of generally 8-12 rays of various 

 lengths, several spikes sessile or clustered in the involucre: Bpikelets oblong or 

 linear-oblong, 6-12 mm. long, yellow, blunt, 40-50- flowered : scales ovate, 

 nearly 1.5 mm. long: achenes oblong, about 0.8 mm. long, brown, pinched at 

 both ends. Everglades. (Cuba, Ant.) 



6. O. altemifollus L. Perennial 0.5-2 m. tall: leaves without blades: scapes 

 often tufted : bracts of the involucre numerous, pliable, elongate-linear, spread- 

 ing or slightly drooping: umbel compound, the longer rays 2.5-9 cm. long or 

 more: spikelets ovate to linear-oblong, 1.5-2.5 mm. wide; scales spreading: 

 achenes obovoid, about 0.8 mm. long, brown. Everglades. Nat of Africa. 

 (Ber., Cuba, Ant.) UMBRELLA-PLANT. 



