574 CYPERACE.i:. (sedge family.) 



* * Spikelet ci^/indrical, many-Jlowered, 1 - 2' long ; scales in several ranics, Jinn- 



coriaceous with scarioLis margin, pale, nerveless or faintly striate ; culms large 

 and stout (2-4° high) ; basal sheaths often leaf bearing. 



2. E. equisetoides, Torr. Calm terete, knotted as if jointed bij many 

 cross-partitions ; achene smooth (the minute reticulation transversely linear- 

 rectangular), with a conical-beaked tubercle. — Shallow water, R. I. to Fla., 

 Avest to Mich, and Tex. 



3. E. quadrangulata, K. Br. (PI. 3, fig. 6-9.) Culm continuous and 

 sharply A-angled ; acliene fnely reticulated, with a conical flattened distinct tu- 

 bercle. — Shallow water, central N. Y. to Mich., and southward ; rare. 



§ 2. Spikelet terete and turgid-ovate, much thicker than the very slender culm; 

 scales tliin-coriaceous or firm-membranaceous, persistent, ovate ; style 3-cleft; 

 bristles stout, barbed downward {or sometimes upward), as long as the striate 

 and pitled-reticulated triangular acliene and its tubercle; culms tufted from 

 fibrous roots, 1-2° high. 



4. E. tuberculosa, R. Br. (PI. 3, fig. lO.) Culms fiattish, striate ; spike- 

 let 3-6" long, many-flowered; tubercle fattish-cap-shaped, as large as the body 

 of the acliene. — Wet sandy soil, from Mass. along the coast to Fla. 



5. E. tortilis, Schult. Culms sharply triangular, capillary, twistingwhen 

 dry; spikelet 2-3" long, few-flowered; conical-beaked tubercle much smaller 

 than the achene. (E. simplex, Torr.) — Eastern shore of Md. to Fla. 



§3. Spikelets terete, much thicker than the culm, many-flowered ; scales imbri- 

 cated in many or more than 3 ranks, thin-membranaceous or scarious, with a 

 thicker midrib, usually brownish or purplish, sometimes deciduous. 



* Style 2-cleft {often 3-cleft in n. 7 and 10) and the smooth achene lenticular: 



culms slender or thread-form, terete or compressed. 



+- Annuals ; culms tufted, from fbrous roots. 



6. E. capitata, R. Br. Culms terete, :^-8' high or more ; spikelets ovate 

 to oblong (1-3" long), obtuse, 15-40-flowered; scales thickish, vound-oySLte, ob- 

 tuse, brown or brownish with green keel and paler margins ; stamens 2 ; achene 

 obovate, black, about equalling the 6-8 bristles, tipped with a flattened or sau- 

 cer-shaped tubercle. ( E. dispar, E. J. Hill.) — In sand or gravel near sloughs, 

 Md. {Canby) to Fla. and Tex.; N. Ind. {Hill). (S. Am., etc.) 



7. E. OVata, R. Br. Culms nearly terete, 8- 14' high; spikelet globose- 

 ovoid to ovate-oblong, obtuse, 1 - 6" long (dull brown) ; scales very obtuse, densely 

 crowded in many ranks; style 3- (rarely 2-) cleft ; achene obovate with narrow 

 base, pale-brownish, shining, shorter than the 6-8 bristles, broader than the 

 short-deltoid, acute and flattened tubercle. (E. obtuSa, Schult.) — Muddy places, 

 N. Brunswick to Minn., south and Avestward. Variable as to the length of its 

 bristles. A low form, with smaller and more narrowly obovate achenes, and 

 the bristles very short or none, is E. diandra, Wright. A dwarf form occurs 

 with very small and few-flowered heads. (Eu.) 



8. E. Engelmanni, Steud. Like the last; spikelets usually narrowly 

 cylindrical and acute or acutish, 2 - 8" long ; achene broad and truncate, the 

 tubercle covering the summit ; bristles not exceeding the achene. (E. obtusa, 

 var. detonsa, Gray.) — Mass. to Peun. and Mo. 



