28 CYPERACEAE. 



oval, 2.5-3 mm. long, blunt, closely imbricate, delicately ribbed: achenes 

 elliptic or slightly broadest above the middle, 1.5 mm. long, dark-brown, dull. 

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



15. C. echinatus (Ell.) Wood. Perennial, 1-5 dm. tall: leaves pale-green; 

 blades 3-4 mm. wide: umbel 6-13-rayed: rays filiform, their sheaths short, 

 mucronate: spikelets 4-8 mm. long, linear, jlat, capitate in globose heads: 

 scales thin, pale-green, appressed, ovate- lanceolate, acute, 9-13-nerved, with 

 narrow scarious margins: achene oblong-obovoid, 2 mm. long, about twice as 

 long as thick. Pinelands. (Ber., Ant.) 



16. 0. brunneus Sw. Perennial, 3-7 dm. tall: leaves overtopped by the scape; 

 blades 2-7 mm. wide, smooth, sometimes involute: umbel compound, capitate, 

 or 3-5 of the rays becoming 1-7 cm. long: spikelets linear or linear-lanceolate, 

 10-15 mm. long, chestnut-colored, densely crowded: scales oval or ovate-oval, 

 nearly 3 mm. long, often apiculate, conspicuously ribbed: achenes elliptic- 

 obovoid, fully 1.5 mm. long, dark-brown. [C. Ottonis BoeckL] Coastal sand- 

 dunes. F. K. (Ber., Bah., Cuba, Ant.) 



2. FUIEENA Rottb. Caulescent herbs with many-flowered terete spikelets 

 in terminal and axillary clusters, or rarely solitary. Scales spirally imbricate, 

 awned, the 1 or 2 lower commonly empty. Flowers perfect. Perianth of 3 

 ovate, oblong, or cordate-ovate, stalked, often awned sepals, usually alternating 

 with as many downwardly barbed bristles. Achene stalked or nearly sessile, 

 sharply 3-angled, smooth. UMBRELLA-GRASS. 



LBTM mere bladeless or nearly hladeless sheaths : stem reclining. 1. F. Hrpoldea. 

 Leaves with well-developed blades : stem erect. 2. F. brcviseto, 



1. F. scirpoidea Mich*. Plants reclining: leaf-blades obsolete or ru-iinu-ntary: 

 spikelets not bristly; scales mucronate: sepal-blades oblong-ovate, not ciliate: 

 achene-body fully 1 mm. long, longer than wide, stipitate. Everglades. 



2. F. brevlseta Coville. Plants erect: leaf -blades linear: spikelets bristly; 

 scales with recurved awn-tips: sepal-blades ovate-cordate, ciliate: aclxMic- 

 body less than 1 mm. long, fully as wide as long, not stipitate. Everglades and 

 low pinelands. 



3. SCIBPU8 [Tourn.] L. Caulescent or scapose herbs, the leaves some- 

 times reduced to basal sheaths. Spikelets solitary, capitate, spicate, or uiul-.-l 

 late, usually involucrate. Scales spirally imbricate, the 1-3 lower sometimes 

 empty. Flowers perfect. Perianth of 1-6 slender or rigid, barbed, pubescent 

 or smooth bristles, or rarely none. Achene triangular, lenticular, or plano- 

 convex. 



1. 8. valldus Vahl. Scapes stout, terete, smooth, 1-3 m. tall, sometimes 2 

 cm. in diameter, sheathed below: involucral bract solitary, erect, shorter than 

 the umbel: umbel compound, appearing lateral, it- primary rays 3-10 cm. 

 long: bracts 1 i near- lanceolate : spikelets becoming oblong-cylindric, in mostly 

 capitate clusters of 2-6, sessile or some of them peduncled, 5-10 mm. ion-. 

 34 mm. in diameter: perianth-bristles 4-6, downwardly barbed, equalling or 

 longer than the acbene: achenes plano-convex, obovoid, 2-2.5 mm. long, gray, 

 abruptly mucronate, dull. Everglades and stream-banks. (Ber., Bah., Cuba, 

 Ant.) GREAT- BULRUSH. 



4. ELEOCHABI8 R. Br. Scapose herbs. Leaves reduced to sheaths or 

 the lowest very rarely blade-bearing. Scapes simple. Spikelets solitary, 

 terminal, erect, several -many-flowered, not involucrate or rarely with 2 small 

 subtending bracts. Scales spiral. Perianth of 1-12 bristles, usually retrorsely 



