Scirpns. CYPERACE.E. 217 



the spikelets in a terminal (or apparently lateral) involucrate cluster or coniponn<l 

 umbel-like panicle, or solitary. 



A cosmopolitan genus of nearly 250 species, of which about 30 arc foun.l in the United States. 



§ 1. Spikelet solltari/, small, with a sinr,le erect involucral bract : bristles no^ie : 



^ stems low and slender. — Isolepis, Lenth. 



1 S nparius,Spreng. Stems tufted, from fibrotis roots, very slender and often 



setaceou .2 to 6 o nrely 10 inches high, sheathed at base, the upper sheath usually 



bearinc^ a short slender leaf : involucral bract 1 to 10 lines long or nearly wanting : 



S 1^ ovate to oblong-ovate, U to 2l lines long : scales pale or often deep brown, 



vTh a pale prominent midvein, conclave, obtuse or pointed : s amens usually 3 : 



tvle 3 Xft • nuSet triangular-obovoid with distinct angles, the sides convex smooth 



:?Lilly gnuuilar, notltriate nor ribbed, d^-k brown when -^^-^^^ ^^Vf 



V 1 t Pni^fK ¥1 Anc;h' vii 327 Isolepis riparia,K. hv. ; ±looK. l. -Ci. 



I^oXto... Pacif. R. Rep. iv. 153. S. pygm^us, Gray Proc. Amer. Acad. vu. 

 392. S. setaceAis, Linn., var., Boeckeler, Lmna^a, xxxvi. oW. 



Frequent in marshy places near the coast from Santa Barbara to Oregon ; also in South America, 

 Australia, Africa and the Mediterranean region. 



9 S carinatus Gray, 1. c. Resembling the last in habit, the slender stems 

 tri?n.L rSielM 1 to 4 inches h&i, with a short leaf at base : spikeM 



arefy 2 or 3) greenish or tinged with brown, .5 - lO-flowered ; scales m 4 ranks 

 very broadly ov^te, strongly carinate and boat-shaped, acute, gibbous m fmit and 

 retaining tlfe brown nutfet, which is very broad, acutely triangular, smooth, over 

 half a line long, with a broad scar at the summit. - Boeck 1. c. 498 holep^s cari- 

 nata, Hook. & Arn. ; Torr. Gyp. 349. /. koilolepis, Steud. Gyp. 318. 



In swamps about San Francisco, abundant with the last (5oWcr); Santa Rosa Creek (^^^^ 

 loX MeXino County ^Bolander); in the Gulf States, from Alabama to Arkansas and Texas. 



§2 Bristles present, retrorseh/ barbed or ciliate, not elongated: stems mostlg 



tall and stout. — Euscirpus, Benth. 



* Inflorescence apparentbj lateral, with a single erect involucral leaf. 



-I- Stem terete or nearhj so. 



4-f Stem leafg at base : spikelets in a sessile cluster. 



3 S NevadensiS, Watson. Stems clustered, from a running rootstock, a foot 

 or two'hi"h, very slender, somewhat flattened above: leaves nearly equalling the 

 stem deei3ly channelled or revolute, very rough on the margins, sharply acute : 

 spikelets 1 to 8, ovate-oblong, acute, 4 to 10 lines long; scales brown and shining, 

 ovate slightly carinate, acutish : bristles 1 to 3, not half the length of the nutle : 

 style 2-cleft : nutlet broadly ovate, plano-convex, acute, a line long. — l>ot. Km^ 



Borders of Mono Lake, on alkaline soil {Brey,er, n. 18i6); at Soda Lake, Nevada, Watson. 

 ++ ++ Stem leafless or nearly so : spikelets itmbelled. 



4 S lacustris, Linn. Stem stout and tall, from creeping rootstocks terete or 

 very obtusely triquetrous above, leafless or the upper basal sheaths with a short 

 terete leaf : i:nvolucral bract stout, shorter than the inflorescence : ^P^^f ^'^^ ^,;;™;;^^^' 

 solitary or more or less clustered, in an irregularly compound umbel, oW<mg-ov d, 

 3 to 6 lines long ; scales broadly ovate, very obtuse or usually «^^^;^^-^\"^^^; , "^J^T" 

 nate, ciliate: bristles usually 6, slender with scattered liarbs, about ^q- Img^^e 

 obovate plano-convex nutlet : style usually 2-cleft. - Reichenb. 1. c, t. 306-306 , 

 Boeck. 1. c. 712 ; Benth. 1. c. 333. S validm, Yahl. 



