Carex. CLX. CYPERACEiE. 577 



A. Spike single. 2. Dicecious. 



2. C. Davalliana. Smith. 



Spike oblong, rather loose-flowered; pcrig. ovate-lanceolate, attenuate, 

 convex, terete, recurved, longer than the ovate glume ; st. and Ivs. are usually 

 serrulate.— Wayne Co., N. Y., Sartvxll. 



3. C. ExiLis. Dewey. 



Fertile spike ^ below, ovate, rather densely-flowered ; perig. ovate-lanceo- 

 late, convex on both sides, diverging, serrulate on the margin, a little longer 

 than the ovate, acute glume ; Ivs. setaceous ; st. 12 — 20' high. — Grows in Dan- 

 vers and Ipswitch, Ms., Oakcs, in N. Y. and N. J. May. 



/?. squamacea. Dew. Spike often an inch long, having many ^^ glumes at the 

 base and few perig. at the summit. — Longer than the other, and grows with 

 it in Ipswich, Mass., Oakes. 



B. Spikes several, androgynous. 



1 . Stamens variously situated — above, belovj, or in the middle ; sometimes dimcious. 



4. C. STERILIS. Willd. 



Spike compound, ^ below, often dioecious ; spikelets 4 — 6, ovate, subap- 

 proximate ; perig. ovate, acuminate or subrostrate, bifid, compressed, triquetrous, 

 scabrous on the margin, equaling the ovate, acutish glume ; st. 2f high, erect 

 and stiff. — Wet places, common. 



5. C. BROMoiDEs. Schk. 



Spikelets numerous, alternate, ^ below, sometimes all 9 ; perig. lanceo- 

 late, erect, acuminate, scabrous, nerved, bifid, twice longer than the ovate- 

 lanceolate glume. — Common in small bogs, in wet places. 



6. C. siccATA. Dewey. 



Spikelets numerous, ^ above, often wholly ^, ovate, close or approximate ; 

 fr. ovate, lanceolate, acuminate, compressed, nerved, bifid, scabrous on the 

 margin, equaling the ovate and lanceolate glume. — Sandy plains, Westfield, 

 Mass., Davis; Ipswitch, Mass., Oakes ; widely spread over the country, but not 

 abimdant. 



7. C. Sartwellii. Dewey. 



Spikelets 12 — 20, ovate, sessile, compact, bracteate, lower ones especially 

 fructiferous ; upper often J^ ; perig. ovate, lanceolate, convexo-concave, subu- 

 late, short, 2-toothed, a little longer than the ovate and acute glume ; Ivs. flat, 

 linear, shorter than the stem. — Junius, Seneca Co., N. Y., SartweU. 



2, Stamens at the summit of the spikelets. 

 ai Cephalous, or. fruit in heads. 



8. C. CEPHALOPHORA. Willd. 



Spikelets ovate, densely aggregated into an ovate head, bracteate, about 5; 

 perig. ovate, acuminate, compressed, bifid, scabrous on the margin, with a short, 

 ovate, and scabro-cuspidate glume which equals it; st. 8 — 16' high. — Borders 

 of fields and woods, common, but not abundant. 



9. C. vui.piNoiDEA. Michx. (C. vulpinceformis. Vuckerman. C. multi- 

 flora. Muhl.) — Spikelets o'/ate-oblong, obtuse; spike decompound, bracte- 

 ate, conglomerate ; perig. ovate, acuminate, densely imbricate, bifid, tripli- 

 nerved, diverging, a little shorter than the ovate-cuspidate glume ; st. obtusely 

 triangular, round and leafy towards the base. — Common in fields. 



0. microspcrma. Dew. (C. microsperma. Wahl.) Spikelets closely aggregaied, 

 whole spike less compact; perig. more convex, shorter, less acuminated into a 

 beak, very abundant. — Grows with the other, in dry and moist situations. 



10. C. SETACEA. Dewey. 



Spikelets ovate, alternate, obtuse, conglomerate, bracteate ; perig. ovate- 

 lanceolate, acuminate, compressed, bifid, some diverging, about equal to the 

 ovate-lanceolate, awned glume ; st. 2f high, acutely t riangular, scabrous above 

 and striate. — Wet places — not abundant. 



11. C. Mqhlenbergu. Schk. 



Spikelets alternate, obtiisp, npprnximatc. with a long bract at the lower 



