494 CYPERACE.fi (SEDGE FAMILY.) 



16. C. Ui'ayil, Toir. Culm thread-form, wiry (6'- 12' high) ; loives 

 bristle-shaped, channelled; uinbid simple, 4 - 6-roy7 ,- spikes 5-10 /// a loose head, 

 spreadiiH/, 5 - 7-flo\vorcd, the joints of the axis winyed; scales rather obtuse, groen- 

 ish-chcstnut-color; achcniuin obovate, minutely pointed. Barren sandy soil, 

 Rhode Island to New Jersey, near the coast. Aug. (Approaches the next.) 



17. C. filiculillis, Vahl. Culm slender, wiry, often reclined (8'- 15' 

 high ) ; leaves linear ( 1 " - 2" wide ) ; spikes numerous and chut:. n<l in on< s< ssile dense. 

 head, or in 1-3 additional looser heads on spreading rays, 6 - 10 flowered ; joints oj 

 the a.ris naked ; scales blunt, greenish ; aehenium obovate, short-poinicd. (C. ma- 

 nscoides, Ell.) Dry sterile soil; common, especially southward. Aug. 



4 4. MAilfSCUS, Vahl. Style 3-cleJl : the achcnium triaiujnlar : stamens 3 

 spikes 1 -few-flowered, scarcely flattened ; the 2 lotver scales short and empty : oth- 

 erwise as in 3. 



18. C. OVlllftriS, Torr. Smooth; culm sharply triangular (6'- 12' high) ; 

 umbel 1 -6-rayed; spikes in globular dense heads, 2-4-Jlotvered, short and thick: 

 joints of the axis winged ; scales ovate, blunt, greenish ; achenium obovoid. U 

 (Kyllingia. Michx.) Sandy soil, S. New York to lilino's and southward. 

 Aug. -Oct. Heads barely ' in diameter, of 50-100 spikes. 



19. C. retrofit CtllS, Torr. Culm minutely down}/ like the leaves, rough 

 on the obtu.-ish angles (l-3 high) ; umbel many-rayed; spikes slender, awl- 

 gna/H-d, very numerous in obovate or oblong heads terminating the elongated 

 rays, soon rcflcxed, \-2-flotoered in the middle; scales usually 4 or 5, the two 

 lowest ovate and empty, the fertile lanceolate, the uppermost involute-awl-shaped ; 

 achenium linear. 1J. (Scirpus retrofractus, L.) Sandy fields, New Jersey to 

 Virginia, and southward. Aug. Spikes ' long, 50- 100 in a head, greenish. 



2. KYLL.INGIA, L. KVLLINGIA. 



Spikes of 3-4 two-ranked scales, 1 - 1^-flowered ; the 2 lower scales minuto 

 and empty, us in Cypcras 4 , otherwise as in Cyperus 1 (viz. stylo 2-cleft; 

 achenium lenticular) : but the numerous spikes densely aggregated in solitary 

 or triple sessile heads. Involucre about 3-leaved. (Named after Kylling, a 

 Danish botanist.) 



1. K. pillllila, Michx. Head globular or 3-lobed, whitish-green (4" 

 broad) ; spikes strictly 1 -flowered ; upper scales ovate, pointed, rough on tlie 

 keel; stamens U; leaves linear. Low grounds, Ohio to Illinois, and southward. 

 Aug. Culms 2' -9' high. 



3. DULICIIIUin Richard. DDLICHIUM. 



Spikes many- (6- 10-) flowered, linear, flattened, sessile in 2 ranks on axillary 

 solitary peduncles emerging from the sheaths of the leaves. Scales 2 -ranked, 

 lanceolate. Perianth of 6-9 downwardly barbed bristles. Staincm 3. Style 

 2-cleft above. Achenium flattened, linear-oblong, beaked with the long persist- 

 ent style. A perennial herb, with a terete simple culm (l-2 high), jointed 

 ttnd leafy to the summit; the leaves short and flat, linear, 3-ranked. (The nauic 

 oi' a G'^ek island ; its application unexplained.) 



