570 CYPERACeJE. (sEDGfe FAMILY.; 



^2. CYPEKUS proper. Achene triangular ; spikelets usually man ij- flowered^ 

 more or less flattened , with cannate scales, the rhachis marginless or nearly 

 so {winged in n. 12). 



* Stamen 1 ; spikelets short and small (li-5" long) in globidar heads, ovate or 



linear-oblong, many-floicered ; achene oblong -obov ate to linear. 

 •*- Low annuals; involucre 2- 3-leaved ; heads few; scales pointed. 



6. C aristatUS, Rottb. Dwarf (1-5' high); spikelets chestnut-brown, 

 oblong becoming //?«e«r, 7 - 13-flowered, in 1-5 ovate heads (sessile and clus 

 ■;ered, or short-peduncled) ; scales nerved, tapering to a long recurved point ; 

 achene obloug-obovate, obtuse. (C. inflexus, Muhl.) — Sandy wet shores; 

 common. Sweet-scented in drying. 



7. C. acuminatus, Torr. Slender (3-12' high); spikelets ovate, be- 

 coming oblong, 16-30-fluwered, pale; scales obscurely 3-nerved, short-tipped ; 

 achene oblong, pointed at both ends. — Low ground, 111. and southwest ward. 



4-H- Tall perennial (1 -4° high) ; heads many, greenish ; scales pointless. 



8. C. calcaratUS, Nees. Culm obtusely triangular ; leaves and involucre 

 very long, keeled; umbel compound, many -rayed ; spikelets ovate (H" long), 

 in numerous small heads" achenes pale, linear, on a slender stipe ; scales nar- 

 row, acutish, obscurely 3-nervea. (C. virens, Gran, in part; not Miclix. C 

 Luzulie, var. umbellatus, Britt.) — Wet places, Dei. to Fla. and Tex. 



* * Stamens 3 (2 in C. fuscus) ; spikelets clustered on the rays of a simple umbel 



{or in a single sessile head) ; scales mostly green or greenish and many-nerved, 

 abruptly sharp-pointed ; achene obovate, sharply triangular. 



•i-Low annuals. 



9. C. eompressus, L. Culms 3-9' high, with a simple sessile or a few 

 umbellate clusters of oblong to linear spikelets (15-30-flowered and 3-8" 

 long) with crowded strongly keeled and very acute pale scales. — Sterile fields 

 along the coast, Md. to Fla. and Tex. ; also adventive near Philadelphia. 



C. FUSCL'S, L. Of similar habit; spikelets much smaller (2-4" long), 

 the thin brown scales (greenish only on the keel) Ijarely acutish and very 

 faintly nerved. — Revere Beach, Mass. {Youitg) ; on ballast at Philadelphia. 

 (Adv. from Eu.) 



-t- 4- Perennial, propagating from hard clustered corms or bulb-like tubers. 



10. C. Schweinitzii, Torr. Culm rough on the angles (1 -2° high) ; um 

 bel 4-8-rayed, rays very unequal, erect ; spikelets loosely or somewhat remotely 

 6 - \2flowered, with convex many-nerved scales ; joints narrowly Avinged. — Dry 

 sandy shores and ridges, western N. Y. and Penn. to ]\Iinn. and Kan. 



11. C. filiculmis, Vahl. Culm slender, wiry, often reclined (8-15' 

 high) ; leaves linear {h-2" wide) or filiform ; spikelets numerous and clustered 

 in one sessile dense head, or in 1-7 additional looser heads on spreading rays of 

 an irregular nmbel; joints of the axis naked; scales blunt, greenish. — Dry 

 sterile soil ; common, especially southward. 



12. C. Grayii, Torr. Culm thread-form, wiry (6- 12' high) ; leaves al- 

 most 6m^/e-s/m;)er/, channelled ; umbel simple, 4- &-rayed ; spikes 5-10 in a 

 loose head, spreading ; joiyits of the axis ivinged ; scales rather obtuse, greenish- 

 e-hestnut-color. — Barren sands, Plymouth, Mass., to N. J., near the coast. 



