ORDER 155. CYPERACE.E. 745 



18 R. gracilenta Gray. Culms 1 to 2f high, very slender or filiform, smooth ; 

 Ivs. linear-setaceous, much shorter than the stem ; corymbs small, fasciculate, the 

 lateral on slender peduncles exserted from the sheaths; spikes ovoid; glumes 

 ovate, acute, dark brown; bristles 6, a third longer than the roundish-ovoid acheni- 

 um ; tubercle flat, subulate, as long as the achenium. Dry grounds, N. Y. to Fla. 



19 R. filifolia Torr. (nee Kuntb). Culm filiform, G to 12 to 18' high, Ivs. fili- 

 form, or almost capillary, many, much shorter; spikes very small (1" long), in 

 2 or 3 small fascicles, the lateral pedunculate ; setce 6, upwardly scabrous-hispid, 

 as long as the roundish-ovate, lens-shaped, smooth achenium and the hispid-scab- 

 rous tuberck. N. Car. to Fla. Its hispid tubercles distinguishes it from Nos. 1 7 

 and 18. 



20 R. Baldwin!! Gray. Culms slender, acutely 3-angled, 2 to 3f high ; Ivs. linear, 

 acute, keeled, 2 ' wide, glaucous, not ciliate, spikes ovate, in a crowded, fasciculate, 

 terminal corymb; sctce 12. upwardly hispidulous, as long astho smooth, roundish - 

 ovate achenium ; stam. 3. Pine barrens, Ga. 



21 R. dodecandra Baldw. Culm rigid. 3-angled, 1 to 3f high; Ivs. rigid, cori- 

 aceous, keeled, rough-edged, broadly linear (2 to 4," wide), all nearly equaling tho 

 culm at first, at length the culm longer; spikes ovate (lance-ovate when young), 

 4'' long, light chestnut color, pedicellate, in 4 to G pedunculate corymbs ; setae 6 to 

 12, as long as the large (IV' diam.), roundish, smooth achenium; stam. 10 to 12, 

 much longer ; tubercle broad, depressed. Bogs, S. Ga., Fla. (R. megalocarpa 

 and pyncocarpa Gray.) 



22 R. glomerata Vahl. Culm slender, smooth, leafy, a footer more high; Ivs. 

 flat, carinate, rough-edged ; corymbed fascicles very remote, in pzirs, axillary and 

 terminal; spikelets lanceolate; glumes keeled, mucronate, brown; ach. obovoid 

 or cuneiform, very smooth as long as tho tubercle ; setae G, rough, backwards. 

 In bogs, Can. to Fla. July, Aug. 



23 R. cephalantha Gray. St. 2 3f high, triangular, stout: Ivs. 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 G, twice longer than the achenium ; ach. 

 roundish-ovoid, a little compressed, very obtuse. X. J. pine barrens. 



24 R. fascicularis Nutt. Culm teretish, 1 to 2f high, veiny ; Ivs. narrowly linear. 

 much shorter; spikes small (1J" long), fuscous brown, densely fascicled, in several 

 terminal fascicles, and usually several axillary ones ; setee half as long as the 

 roundish-obovate achenium. -S. Car. to Fla. Inflorescence quite variable, some- 

 times copiously terminal, again scattered down the culm. 



25 R. ciliata Vahl. Plant light glaucous; culm 8' to 2f high, ancipital. striate ; 

 Ivs. lance-linear, short, obtusish ; spikes elliptical, chestnut-colored, all collected 

 into a dense terminal fascicle with several short bracts ; setae very short, at the 

 baae of the roundish, lenticular achenium. N. Car. to Fla. 



26 R. distans Nutt. Culm slender, wiry, teretish, 1 to 2f high; Ivs. linear se- 

 taceous, shorter, mostly at base ; spikes small (1" long), ovate, in a terminal fasci- 

 cle, usually with 1 or 2 lateral, somewhat distinct fascicles ; seta; upwardly his- 

 pidulous, about as long as tho broad, ovate, smooth achenium which is not half as 

 large as in R. glomerata. N. Car. to Fla. Name not very appropriate. 



15. CERATOSCHQE'NUS, Noes. (Gr. KKpag,arag, a horn, oxolvo$, 

 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. 2f Stems leafy. Corymbs 

 compound. 



1 C. longirostris Torr. Glabrous and glaucous ; culm 3 4f high, triangular ; 

 Ivs. 1216' by 4 6'', flat, rough-edged ; Ms. 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 



