SCI.KRU. CLX. CYPERACEJE. 575 



* * Achenium rugose. 



7. R. CYMOSA. Nutt. (Schcenus. Willd.) 



St. i 2f high/ triangular, angles acute; radical Ivs. shorter than the 



o^m. cauline rising above the stem ; corymbs 34, the terminal largest ; spike- 

 lets ovoid, in close fascicles of about 5 ; glumes broad-ovate, dark brown ; 

 bristles 6. | as long as the broad-ovate, transversely rugose achenium ; tubercle 

 Depressed, much Shorter than the ach. N. J. to La. Jl., Aug. 



8. R. TORREYANA. A. Gr. 



SI. 2f high, slender, caespitose, striate ; Ivs. setaceous, radical, 6 10" 

 long, cauline much shorter ; corymbs diffuse, the lateral, if any, on short pedun- 

 cles ; spikelets ovoid, pedicellate or sessile ; glumes ovate, mucronate, brown ; 

 bristles 6, scarcely half as long as the oblong-ovate achenium ; tubercle short, 

 nearly as broad at base as the achenium. N. J. Torrey. JL, Aug. 



15. CERATOSCHCENUS. Nees. 



Gr. Kepas, orof, a horn, o-^oiroj, rush ; alluding to the long, persistent style of the achenium. 



Spikelets 2 5-flowered, one flower $ , trie rest cT ; 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 on the smooth, compressed achenium. % Stems leafy. 

 Coi'ymbs compound. 



1. C. LONGIROSTRIS. A. Gr. (Schcenus longirostris. Michx. S. cornicula- 

 tus. Lam. Rhyncospora comic. A. Gr.} Glabrous and glaucous; st. 



3 4f high, triangular ; Ivs. 1216' by 46", flat, rough-edged ; fls. in very 

 large, terminal and axillary corymbs, terminal one the largest ; spikelets 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, subu- 

 late, horny style. Ohio ! to Flor. Common in wet places Aug. 



2. C. MACROSTACHYA. Torr. (Rhyncospora ejusd.) 



Glabrous; st. 2 3f high, triangular; Ivs. 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 ache- 

 nium ; style persistent, nearly 4 times as long as the achenium. Mass. Rob- 

 bins. ! 



16. CLADIUM. Browne. 



Flowers c? $ 9 ; glumes imbricated somewhat in 3 rows, lower 

 ones empty ; bristles ; stam. 2 ; style 2 3-cleft, deciduous ; ache- 

 nium subglobose, the pericarp hard, thickened and corky above. 

 T-l Stem leafy. Corymbs or panicles terminal and axillary. 



C. MARiscolDEs. Torr. (Schocnus. Muhl.} Bog Rush. 



St. terete, leafy, 20 30' nigh, hard and rigid; IDS. narrowly linear, chan- 

 neled above, rounded beneath, much shorter than the stems ; bracts short; umbels 

 1 3, erect, the lateral on long exserted peduncles ; rays 3 7, some of them 

 rery short; spikelets aggregated in heads of 4 8, lance-ovate, 3" long; glumes 

 ,awny-brown, about 6, the upper usually $ , the next J\ and the rest empty ; 

 tcA. ovoid, short-beaked with the remains of the 3-cleft style. Bogs, Can. to 

 Penn. July. 



TRIBE 3. SCLERE J3, Flowers monoecious or diclinous. Achenium naked 

 (without a perigynium), more or less hard and bony. 



17. SCLERIA. 



Gr. trxAityjo j, hard ; alluding to the indurated shell of the fruit. 



Flowers aiclinous, fertile spikelets 1 -flowered, glumes fasciculate; 

 perigynium cup-shaped or ; achenium globose, ovoid or triangular, 

 with a thick, bony pericarp ; style 3-cleft, deciduous. ^j- Stems leafy. 

 Spikelets in spikes, fascicles or panicles. 

 49 



