492 CYPERACEJE. (SEDGE FAMILY.; 



5. C. eryfhrorllizos, Muhl. 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 hori/.ontally, linear, flatfish (%' long), bright chestnut-colored; 

 scales lanceolate, macro mil a to. < Alluvial banks. Penn. to Wi.- cousin? and 

 southward. August. Root fibrous, red. 



3. CYPERUS PROPER. Style 3-deft : achenium triangular : spikes many- 

 flotr, red, jlat or almost tin te ; only the. lowest scale empty ; the joint* of the a.ris 

 narrotcly wing-margined or naked. 



* Roots annual, fibrous: no creeping rootstocks : cnlm triangular: spikes uwl-shttpal, 

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



'rays of lite simple or mostly compound ample and open umbel: involucre very long, 

 3 - several-leaved : scales of the spike pointless; the joints of the axis winyed l>y a 

 pair of adherent scales : stamens 3. 



6. C. ItfichauxiailllS, Schultes. Culm stout (lhigh); rays short; 

 spikes linear-thread-shaped, teretish when mature (%'-%' lonp;) ; the joints of its a.ris 

 short and winged inth very broad scaly margins, which embrace, the ovate 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. EllgClllianni, Stetid. Culrn -3high; rays mostly short; 

 spikes filiform, almost terete (about \' long), sometvhat remotely 5 - 9-flowered, the 

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

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

 mss. C. stenolepis, 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 base is never 

 touched by the one next beneath on the same side. 



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

 (l-3 high) ; some of the rays elongated, their sheaths 2-hristled ; sjtikes liiicar- 

 awl-shaped, but flat, 8 - 1 5-flowered, very numerous, reflexed with age; the 

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

 eral-nerved, much longer than tl>e linear-oblong achenium. Var. sj>Kci6sus (C. 

 speciosus, !??/(// Tbrr.) is a rank state, with some of the partial umbels fur- 

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

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



* * Rwls annual, Jihrons : stamen only 1 : culm slender, low (I 7 -12' high) : sj>/7.-es 

 flat, oblong-linear <>r orate, crowded into heads on llie j'ciu simple or compound rays: 



involucre 2 SMlectwerf; scales of the .s/</7>- ////// spreading points : joints of the ,tri.t 

 sKghtly "/ not at till nturfjined. 



9. C. iiaiS, XEIS, Muhl. Dwarf (l'-5' high); sy>/7v.s- iJ'tong-Ifnmr, 7-13- 

 flowered, collccteil in 2-3 ovate heads (either sessile and clustered or short-pe- 

 dui'.cled) ; st:ali-ti i/erfed, ta/xr/in/ info a Ion*/ reeurred point aeheniujn ol)ovat<', 

 obtuse. Sandy w<'t sliores ; common. July - Sept. Swet-scer ted in drying. 



