CYPEEACEAE. 21 



Rachis breaking up into 1-fruited joints : spilvelets nearly 

 terete. 

 Spikes solitary : scapes filiform, reclining : plants 



perennial. 5. C. floridanus. 



Spikes umbellate : scapes stout, erect : plants annual. 6. G. ferax. 

 Rachis deciduous above the lower pair of scales. 



Achenes narrowly linear-oblong, 2i^-4 times as long 

 as thick. 

 Achenes 2 mm. long, fully 5^ as long as the scale. 7. C. Martindalei. 

 Achenes 1.5 mm. long, less than 5^ as long as the 



scale. 8. C. Utoreus. 



Achenes oblong to obovoid, not more than twice as 

 long as thick. 

 Spikelets with 1-4 achenes. 



Umbel simple or head solitary : leaf -blades rela- 

 tively narrow. 

 Heads dark-brown : scales mucronulate. 9. C. fuligineus. 



Heads green or greenish-brown : scales not 



mucronulate. 10. C. Blodgettii. 



Umbel compound : leaf-blades relatively broad. 11. C. ligularis. 

 Spikelets with 5-10 achenes. 12. C hrunneus. 



1. O. paniculatus Eottb. Annual, 1-4 dm. tall: leaves often 3-6; blades 1-4 

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

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

 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. — Low hammocks and sandy places, L. 

 keys.— [E. K.]— (J?er., Bali., Cuba, Ant.) 



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

 blades about 2 mm. wide: scapes smooth: 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: achenes obovoid, obtuse, dull-brown, about J as long as the scale. — 

 Open hammocks and sandy places, L. keys. — [E. K.] — {Bah., Cuba, Ant.) 



3. C. elegans L. Perennial, pale-green: leaves several at the base of the 

 scape, viscid; blades mostly 2-4 mm. broad, involute above the loose, striate 

 sheaths: scapes tufted, 2-7 dm. tall: umbel simple or compound, usually of 

 3-6 rays: spikelets linear-oblong, 6-12 mm. long, crowded: scales light tan- 

 colored, rhombic-ovate, 3 mm. long, scabrous on the back, with more or less 

 sprea.ling short awn-like tips: achenes obovoid, fully 1.5 mm. long including 

 the subulate beak. — Hammocks and open sandy places, Key West. — (Bah., 

 Cuba, Ant.) 



4. C. esculentus L. Perennial by scaly tuber-bearing rootstoeks: leaves light- 

 green; blades 4-8 mm. wide, the midvein prominent: scapes usually stout, 3-8 

 dm. tall, commonly shorter than the leaves: umbel 4-10-rayed, often compound: 

 spikelets numerous in loose spikes, straw-color or yellowish-brown, flat, spread- 

 ing, 1-2.5 cm. long, about 3 mm. wide, many-flowered: scales ovate-oblong, 

 rather acute, 3-5-nerved : rachis narrowly winged : achenes obovoid, fully 1 mm. 

 long, obtuse. — Waste places and cultivated grounds, Key West. — {Ber., Cuba, 

 Ant.) 



5. C. floridanus Britton. Perennial, bright-green: leaves mostly reduced to a 

 few basal scales and several filiform blades: scapes tufted, erect or reclining, 

 1-7 dm. long, filiform or wiry : umbel capitate, sessile : spikelets linear- subulate, 

 6-10 mm. long, crowded, chestnut-brown, scales broadly oblong, fully 2 mm. long, 

 blunt, closely imbricate, ribbed on the back, very firm : achenes oblong or nearly 

 so, about 1.5 mm. long, dark-brown, dull. — Open hammocks and sandy places, 

 Key West. — (Bah., Cuba, Ant.) 



6. C. ferax Vahl. Annual, 1-4 dm. tall: leaf -blades smooth-margined: umbel 

 often compact, the rays mostly short: spikes yellowish or grayish-brown: 



