578 CLX. CYPERACE, Carex. 
one; perig. ovate, convex above, very smooth, nerved, bifid, scabrous on the 
margin, some diverging, a little shorter than the ovate and mucronate glume; 
st. 12—18' high.—In fields, not very common, readily distinguished from the 
three preceding and following. . 
12. C. CHORDORRHIZA. 
Spikelets 3—5, aggregated into a head, ovate, sessile ; ig. ovate, acumi- 
nate, subrostrate, convex above, equaling the broad, ovate and acute glume; 
st. branching towards the base and sending out roots at the joints; spikes rarely 
bearing only stamens.—Marshes, New York; common, Sartwell. Michigan, 
Cooley. re 
13. C. Pratrea. Dew. 
Spike below branched; spikelets ovate, sessile, 5—7 on a branch; perig. 
ovate-lanceolate, convex both sides, scabrous on the margin, slightly bifid, 
equaling the ovate-lanceolate glume; st. 2—3f high, leafy towards the base.— 
Abundant in the prairies of Michigan, and sparingly found in N. England and 
N. ¥. Resembles C. paniculata. L., which has a much broader ovate glume, 
shorter than the perigynium and is far more paniculate, and for which this has 
been taken. 
14. C. reretiusctLa. Good. ; 
Spikelets ovate, acute, sessile, decompound, brownish, lower one bracteate ; 
perig. ovate, acute, convex and gibbous, scabrous on the edge, spreading, lon- 
ger than the ovate and acute glume; fr. brown; st. 18—36/ high, leafy towards 
the root.—Wet places, common, in tufts. 
15. C. pecomposira. Muhl. 
Spike decompound or paniculate; spikelets very many, ovate, alternate ; 
perig. ovate, convex on both sides, triangular, acutish or short-rostrate, short, 
brownish, glabrous, about equal to the ovate and acuminate, whitish glume; 
st. 18—30’ high—Found in swamps, Michigan, and in Yates Co., N. York, 
Sartwell. : 
16. C. PANICULATA. 
Spike paniculate, often { O, long and spreading; spikelets ovate, sessile, 
6—18 on a branch below, short bracteate ; perig. ovate, acute, gibbous, nerved, 
2-toothed, brownish or tawny, 2-toothed, serrulate on the margin, a little 
shorter than the broad-ovate, short-acute glume ; st. 2f high.—Found in North- 
ern America, and hardly known in the United States. 
b. Perigynia radiating. 
17. C. rosea. Schk. 
Spikelets 3—5, subremote, sessile, alternate, stellate, eyen before maturity, 
lowest long bracteate; perig. oblong-lanceolate, 5—12, convex above, scabrous 
on the margin, 2-toothed, very diverging or even reflexed, twice as long as the 
ovate-obtuse glume; st. 8—16’ high. 
8. radiata. Dew. Spikelets distant, about 3-flowered, with setaceous bracts ; 
perig. oblong, acute; st. 4—8’ high, flaccid or lax, setaceous, with very narrow 
leaves.—Common in pastures and moist woods; the variety is about woods, or 
open places in woods. . 
18. C. reTRorLexa. Muhl. 
Spikelets about 4, ovate, alternate, subapproximate, sessile, bracteate and 
stellate in maturity; perig. ovate, acutish, 2-toothed, subscabrous or smooth on 
the margin, reflexed and spreading, about equal to the ovate and acute glume 3. 
st. about a foot high.—Readily distinguished from the preceding. Woods and 
pastures, not abundant. : 
19. C. stipata. Muhl. 
Spike often decompound; spikelets oblong, aggregated, numerous, bracte- 
ate; perig. ovate-lanceolate, round at the base, plano-convex, nerved, bifid, sub- 
scabrous on the margin, diverging, twice longer than the ovate-lanceolate 
glume; sf. thick, acutely triquetrous, concave on the sides—Wet places and 
marshes, abundant. 
20. C. aLopecéipa. Tuckerman. is cephalophora, 8. maxima. Dew.) 
Spike compound, rather loose; spikelets 8—10, aggregated into an oblong 
