CYPERACE.*:. (sedge FAMILY.) 581 



ish; scales ovate, strongly keeled, mucronate-pointed ; stamens 2 or 3 ; stvlo 

 2-cleft ; bristles none ; achene obovatc-orbicniar, niueroiiato, plano-convex, stronghf 

 wrinkled transverselij. — Wet sliores, 111. to Tex.; also found in E. Mas.s. 

 {I 1 itching s). (Eu.) 



* * * Spikelets in simple or mnsthi com/wunfl umbelhde or ci/mose-pauiclfd 



clusters, many-Jlowered, terete ; involucre of mostlij several flat leaves ; cuhn 



tall, front tujlcd or running rootstocks, triangular, leaf i/, sedge-like : leaves 



rough on the margin ; style mostly 3-clefi. 



■*- Spikelets large (G- 15" long) ; midrib of the scales extended beyond the mostly 



lacerate or two-clef apex into a distinct au-n. 



13. S. maritimus, L. (Sea Club-Rush.) Leaves flat, linear, as long 

 as tlie stout culm (1-3° high), those of the involucre 1 -4, very unequal; 

 spikelets few-several iu a sessile cluster, and often also with 1-4 unequal 

 rays bearing 1-7 ovate or oblong-cylindrical (rusty-brown) spikelets ; awns 

 of tlie scales soon recurved; achene obovate-orbicular, compressed, flat on one 

 side, convex or obtuse-angled on the other, minutely pointed, shining, shorter than 

 the 1-6 unequal and deciduous (sometimes obsolete) bristles. — Saline locali- 

 ties, on the coast from N. Scotia to Fla., and in the interior across the conti- 

 nent. (Eu.) — Yar. macrostachyos, Michx. ; larger, with very tliick oblong- 

 cylindrical heads (1 - I|' long), and longer involucral leaf (often 1° long). 



14. S. fluviatilis, Gray. (Kiver C.) Culm very stout, 3-5'^ liigh ; 

 leaves flat, broadly linear {}' wide or more), tapering gradually to a point, 

 the upper and those of the very long involucre very much exceeding the com- 

 pound umbel; rays 5-9, elongated, recurved-spr ending, each bearing 1 - .5 

 ovate or oblong-cylindrical acute paler heads ; scales less lacerate and awns 

 less recurved; achene obovate, sharply and exactly triangidar, conspicuoush/ 

 pointed, opaque, scarcely equalling the 6 rigid bristles. — Borders of lakes and 

 large streams, W. Vt. to Conn, and Penn., west to Minn, and Iowa. 



•*- ■*- Spikelets very numerous, small {\- 3" long); scales inucronate-pninfed or 

 blunt; umbel-like cymose panicle irregular, compound or decompound ; cuhn 

 2-5° high, unusually leafy ; leaves broadly linear, green and rather soft : 

 bristles very slender, often more or less tortuous and naked below. 



15. S. Sylvaticus, L. Spikelets lead-colored, clustered 3 -10 together at 

 the end of the mostly slender ultimate divisions of the open decomi)ound panicle, 

 ovoid or lance-ovate, 2" long; scales bluntish ; bristles 6, downwanlly barbed 

 throughout, rather exceeding the triangular short-pointed achene ; style 3-cleft. 

 — Along brooks, E. Mass. to N. Y. and E. Penn. 



Var. digynus, Boeckl. Style 2-cleft and the achene not at all angled on 

 the back ; stamens 2, and bristles 4. (S. microcarpus, Presl.) — N. Scotia and 

 N. Eng. to Minn., and westward. 



16. S. atrbvirens, Muhl. Leaves somewhat more rigid; spikelets dull 

 greenish-brown, densely conglomerate (10-30 together) into close heads, these also 

 usually densely clustered in a less compound panicle ; scales pointed ; bristles 

 sparsely and strongly downwardly barbed above the middle, naked below, nearly 

 straight, as long as the conspicuously pointed and obovate-oblong trianirular 

 achene. — Wet meadows and bogs, X. Scotia and N. Eng., west to Minn.. Kan., 

 and the Pacific. 



