62 CYPERACEAE. 



with a pale midvein, concave; bristles none; style 3-cleft; achene 

 3-angled-obovoid, the sides convex, smooth or somewhat granular, 

 dark brown, scarcely 1 mm. long. (5. ripariiis Spreng.) 



Occasional on river bottoms about Los Angeles and Santa 

 Barbara. Resembling Eleocharis in habit. 



2. S. americanus Pers. Perennial by long rootstocks; stems 

 sharply 3-angled, with concave sides, erect, 3-12 dm. high; leaves 

 2-6, narrowly linear, shorter than the stem, keeled; involucral 

 bract solitary, leaf-like, 4-10 cm. long; spikelets appearing as if 

 lateral, sessile in capitate clusters of 1-7, acute, 8-16 mm. long; 

 scales broadly ovate, brown, often emarginate or sharply 2-cleft, 

 the midvein extended into a subulate awn, the margins scarious, 

 ciliate or glabrous; bristles 2-6, retrorsely barbed, shorter than 

 or equaling the achene; style usually 2-cleft; achene obovate, plano- 

 convex, smooth, dark brown, mucronate. (S. pungens Vahl.) 



Occasional on river bottoms about Los Angeles; Santa Ana; San 

 Diego. April-July. 



3. S. olneyi Gray. Perennial by long stout rootstocks; stems 

 stout, 6-25 dm. high; sharply 3-angled with concave sides; leaves 

 1-2, 3-12 cm. long, or sheaths sometimes leafless; involucral bract 

 stout, erect, 1-3 cm. long; spikelets appearing as if lateral, capitate 

 in dense clusters of 5-12, oblong or obovoid-oblong, obtuse, 5-8 mm. 

 long; scales oval or orbicular, dark brown with a green midvein, 

 emarginate or mucronulate, glabrous; bristles usually 6, slightly 

 shorter than or equaling the achene, retrorsely barbed; stamens 3; 

 styles 2-cleft; achene obovate, plano-convex, brown, mucronate. 



Common in marshes and along running streams throughout our 

 range. June-September. 



4. S. lacustris L. Stems stout from creeping rootstocks, terete 

 or rarely obscurely 3-sided, 1-3 m. high, leafless or the basal sheaths 

 bearing a short nearly terete leaf; involucral bract stout, shorter 

 than the inflorescence; spikelets numerous, scattered or more or less 

 clustered in an irregularly compound umbel, oblong-ovoid, 6-10 

 mm. long; scales broadly ovate, obtuse, usually pubescent; bristles 

 6, equaling or longer than the achene, slender, retrorsely barbed; 

 style 2-cleft; achene obovate, plano-convex, abruptly mucronate, 

 grayish. 



Common along streams and marshes. This and the next are 

 commonly called "Tule." June- September. 



5. S. californicus (C. A. Myer) Britton. Much resembling 

 the last in habit and size; stems obtusely 3-angled; involucral bract 

 very short, stoutly subulate; umbel compound; spikelets 6-10 mm. 

 long, oblong; scales brown, ovate, awn-pointed by the excurrent 

 midvein; bristles shorter than the achene, rather stout, strongly 

 ciliate at least below; style 2-cleft; achene obovate, plano-convex, 

 nearly white or brown, narrowed above into a short point, contracted 

 at base, 1-1.25 mm. broad. (S. tatora Kunth.) 



With the last and apparently more common. Typical forms are 

 readily distinguished by the stouter and shorter strongly ciliate 

 bristles, stouter filaments, and smaller achene tapering at the apex. 

 Intermediate forms, apparently hybrids, are occasionally found. 



