23 R. cephaldntha Gray. St. 2 - 3f high, triangular, stout: lvs. linear, very narrow, the lower and radical nearly as long as the stem; hds. roundish, axillary and terminal, dense, 5 to 7" diam., the 2 upper often near; spikelets lance-oblong; glumes ovate-oblong, dark brown; setae 6, twice longer than the achenium; ach. roundish-ovoid, a little compressed, very obtuse. - N. J. pine barrens.
24 R. fascicularis Nutt. Culm teretish, 1 to 2f high, veiny; lvs. narrowly linear. much shorter; spikes small (1 1/2" long), fuscous brown, densely fascicled, in several terminal fascicles, and usually several axillary ones; seta) half as long as the roundish-obovate achenium. - S. Car. to Fla. Inflorescence quite variable, sometimes copiously terminal, again scattered down the culm.
25 R. ciliata Vahl. Plant light glaucous; culm 8' to 2f high, ancipital, striate; lvs. lance-linear, short, obtusish; spikes elliptical, chestnut-colored, all collected into a dense terminal fascicle with several short bracts; setae very short, at the base of the roundish, lenticular achenium. - N. Car. to Fla.
26 R. distans Nutt. Culm slender, wiry, teretish, 1 to 2f high; lvs. linear setaceous, shorter, mostly at base; spikes small (l"long), ovate, in a terminal fascicle, usually with 1 or 2 lateral, somewhat distinct fascicles; setas upwardly hispidulous, about as long as the broad, ovate, smooth achenium which is not half as large as in R. glomerata. - N. Car. to Fla. Name not very appropriate.
15. CERATOSCHŒ'NUS, Nees. (Gr. - a horn, rush; alluding to the long, persistent style of the achenium.) Spikelets 2 - 5-flowered, one flower , the rest ; glumes loosely imbricated, somewhat in 2 rows, lower ones empty; perig. of 5 or 6 rigid, hispid or scabrous bristles; stam. 3; style simple, very long, persistent and crowning the smooth, compressed achenium. - Stems leafy. Corymbs compound.
1 C. longirostris Torr. Glabrous and glaucous; culm 3 - 4f high, triangular; lvs. 12 - 16' by 4 - 6", flat, rough-edged; fls. in very large, terminal and axillary corymbs, terminal one the largest; spikes lanceolate, acuminate, 8" long, loosely fascicled in 4s or 5s on the long peduncles; glumes brown, ovate; bristles shorter than the achenium, which is 2" long, and crowned with the (7") long, subulate, horny style. - Ohio to Fla. Common in wet places. Aug. Rhyncospora cor-niculata Gray.) 2 C. macrostachya Torr. Glabrous; culm 2 - 3f high, triangular; lvs. 1 - 2f by 2 - 4", rough-edged; axillary corymbs subsimple, terminal ones compound; upper spikelets densely fascicled; ach. ovate, smooth; bristles erectly hispid, twice as long as the achenium; style persistent, nearly 4 times as long as the achenium. - Mass. (Robbins). (Rhyncospora ejusd.)
16. CLA'DIUM, Browne. Flowers ; glumes imbricated somewhat in 3 rows, lower ones empty; bristles 0; stam. 2; style 2 - 3-cleft, deciduous; achenium subglobous, the pericarp hard, thickened and corky above. - Stem leafy. Corymbs or panicles terminal and axillary.
1 C. mariscoides Torr. Bog Rush. St. terete, leafy, 20 - 30' high, hard and rigid; lvs. narroioly linear, channeled above, rounded beneath, much shorter than the stems; bracts short; umbels 2 - 3, erect, the lateral on long, exserted peduncles; rays 3 - 7, some of them very short; spikes aggregated in heads of 4 - 8, lance-ovate, 3" long; glumes tawny-brown, about 6, the upper usually , the next , and the rest empty; ach. ovoid, short-beaked with the remains of the 3-cleft style. - Bogs, Can. to Penn. July. (Schoenus, Muhl.)
2 C. effusum Torr. Saw-grass. Culm obtusely 3-angled, 6 to 10f high; lvs. 3 to 10f! long, 4 to 10" wide, tapering to a very long, 3-angled point, margins sharply serrate-barbed; corymbs numerous, decompound, diffuse, approximated and forming a large, elongated panicle; spikes 2" long, 3 or 4 together, brown: ach. ovoid, 1" long. - Ponds and swamps, N. Car. to La. (Hale). A coarse and rank sedge.
17. SCLE'RIA, L. Nut Sedge. (Gr. hard; alluding to the indurated shell of the fruit.) Fowers 8, staminate spikes intermixed, fertile spikelets 1-flowered, glumes fasciculate; perigynium cup-shaped or 0; achenium globous, ovoid or triangular, with a thick, bony pericarp; style 3-cleft, deciduous. - Stems leafy. Spikes in fascicles or panicles.
§ Scleria. Achenium ovoid or globous, base invested with a short perigynium. (*)
* Achenium smooth, ovoid. Perigynium annular, subentire.................................
Nos. 1, 2
* Achenium rugous - warty, globular. Perigynium 6 or 3-lobed............................
Nos. 3, 4
* Achenium reticulated or hispid-rugous, globular. Perigynium 3-lobed.................
Nos. 5. 6
§ Hypoporum. Achenium ovoid-triangular, base fluted. Perigynium none, (a)
a Fascicles 4 to 7, interruptedly spiked. Ach. smooth or rugous..........................
Nos. 7. 8
a Fascicles single, terminal. Achenium ribbed or smooth...........................
Nos. 9, 10
1 S. triglomerata Mx. Whip-grass. Culm erect, acutely triangular, rough, leafy, 3 - 4f high; lvs. linear-lanceolate, rough-edged; spikes lateral and terminal, alternate, in about 3 subsessile, triglomerate fascicles, and much shorter than the leafy bracts; glumes ovate, cuspidate, dark purple; ach. globous, smooth and polished, white, nearly 2" diam., invested at base with an entire, crustaceous rim. - Swamps, in nearly all the States. Jn., Jl.
2 S. leptoculmis. Culm very slender, acutely 3-angled, 2f high; lvs. smooth, flat; sterile spikes elongated (4" long), in 2 fascicles, the lateral one remote from the terminal, on a long, filiform penduncle; glumes dark purple; stam. 3; ach. ovoid, obtuse, white, polished minutely corrugated; perig. annular, with about 8 minute tubercles. - Fla. Pairs of spikelets 3 or 4. (S. oligantha Torr. nee Mx.)