492 CTPERACE.fi. (SEDGE FAMILY.; 



5. C. crytlirorllizos, Mulil. Culm obtusely triangular (2 -3 high); 

 umbel compound, many-rayed; involucre 4-5-lcaved, very long; involuccls 

 bristle-form ; spikes very numerous, crowded in oblong-cylindrical nearly sessile 

 heads, spreading horizontally, linear, flatfish (^' long), bright chestnut-colored; 

 scales lanceolate, nmcronulate. Alluvial banks, Penn. to Wisconsin 1 and 

 southward. August. Root fibrous, red. 



3. CYPEKUS Plioi'ER. Style 3-cleft : achenium triangular : spikes ntany- 

 flowered, Jlat or almost terete ; only the lowest scale empty ; t/te join's of the turit 

 narrowly winy-margined or naked. 



* Roots annual, Jibrous: no creeping rootstocks: culm triangular: spikes aid-shaped, 

 thread-shaped, or very narrowly linear, very numerous, crowded at the summit of the 

 rays of the simple or mostly compound ample and open umbel : involucre very lony, 

 3 - several-leaved : scales of the spike pointless; Hie joints of the axis winyed by a 

 pair of adherent scales : stamens 3. 



6. C. Michail\i;\llUS, Schultcs. Culm stout (lhigh); rays short; 

 pikes linear-thrcad-shaped, tere.tish when mature (^'-^' long) ; tlic joints of its ajcis 

 short and ivinyed with very broad scaly margins, which embrace the orate triangular 

 achenium ; scales ovate, obtusish. Marshes, especially along the coast and 

 large rivers, S. New England to Wisconsin, and southward. Aug., Sept. 

 Flowers 6-20 in the spike, yellowish-brown. 



7. C. Engclllliaimi, Steud. Culm -3high; rays mostly short; 

 spikes filiform, almost terete (about ' long), somewhat remotely 5 - & flowered, the 

 zigzag joints of the axis slender, narrowly wing-margined ; achenium oblong-linear, 

 almost equalling the oblong or oval broadly scarious scale. (C. tenuior, Enytlm. 

 mss. C. stenolcpis, Ton:, probably, though the character docs not accord : the 

 greenish keel or centre was perhaps taken for the whole scale, which is not nar- 

 row, so the name is inapplicable as well as doubtful.) Low banks of streams, 

 Wisconsin, Illinois, Virginia? and southward. Between the foregoing and 

 the next. The scales of the spike are so separated that their bu.se is never 

 touched by the one next beneath on the same side. 



8. . Strigosus, L. Culm mostly stout, bulbous-thickened at the base 

 (l-3 high) ; some of the rays elongated, their sheaths 2-bristled ; spikts liitcar- 

 iwl-shaped, but Jlat, 8 - 1 5-flowercd, very numerous, rcflcxcd with age; the 

 slender joints of the axis narrowly wing-margined ; scales oblong-lanceolate, sev- 

 eral-nerved, much longer than the linear-oblong achenium. Var. SPKCIOSUS (C. 

 gpeciosus, Va/tl? Torr.) is a rank state, with some of the partial umbels fur- 

 nished with a leafy involuccl. Low or rich grounds; common, especially 

 southward. July- Sept. Spikes greenish, turning straw-color, j'- 1' long. 



* * Roots annual, Jibrous: stamen only 1 : cidm slender, low (l'-12' high] : spikes 

 fait, oblong-linear or ovate, crowded into heads on the few simple or compound rays: 

 involucre 2 - 3-leaved : scales of the spike with spreading points : joints of the axis 

 slightly or not at all margined. 



9. C. illfleXHS, Muhl. Dwarf (l'-5 high); spikes oblong-linear, 7-13- 

 flowercd, collected in 2-3 ovate heads (either sessile and clustered or short-pe- 

 d uncled) ; scales nerced, tapering into a long recurved jioint , achenium obovate, 

 obtuse. Sandy 'vet shores : common. Julv - Sept. Swc2t-sccntci1 in drying. 



