580 CYPERACEiE. (SEDGE FAMILY.) 



firm, scarcely at all scarious ; style 3-cleft ; achene smaller, broadly obovate 

 — iu a siugle locality iu Delaware Co., Pemi. ; probably iutruduced from S. 

 Europe. 



4_ -v- Culm triangular, tall and stout, from slender running rootstocks ; spikelets 

 manij-Jiowered , loosely umbellate or curymbed, involucellate-bracted . 



8. S. Canbyi, Gray. Culm (3 - 5° higb) 3-angled, usually sharply so 

 above, obtusely below, the sheath at base extended iuto a luug slender iriau- 

 gular aud channelled leaf (2-4° long) ; iuvolucral leaf similar (-1-8' long); 

 continuing the culm; spikelets oblong (4-6" long), siugle or sometimes pro- 

 liferously 2 or 3 together, nodding on the apex uf the 5-9 long filiform and 

 flattened peduncles or rays of the dichotomous umbel-like corymb, or the cen- 

 tral one nearly sessile ; scales loosely imbricated, oblong-ovate, acute, pale, 

 thin and scarious, with a greenish nerved back ; bristles 6, firm, furnished 

 above with spreading hairs rather than barbs, equalling the slender abrupt 

 beak of the obovate-triaugular shining achene (1^" long). — In a pond near 

 Salisbury, Md. 



^_ H_ 4_ Culm terete, very tall and stout, from a deep running rootstock, leafless 

 or very nearly so; spikelets numerous, clustered in a one-sided compound 

 umbel-like panicle longer than the involucral leaf; involucellate bracts small, 

 scale-like and rusty-scarious ; scales of the spikelets rusty or chestnut-brou-n, 

 scarious, the midrib extended into a mucronate point. 



9. S, laeustris, L. (Great Bulrush.) Culm 3-9° high, i-V thick 

 at base ; spikelets ovate-oblong (3 - 4" long) ; scales mostly a little downy on 

 the back and ciliate ; style 2-cleft ; achene pale and dull, obovate with a nar- 

 rowed base, plano-convex, mucronate-pointed, usually overtopped by the 4-6 

 slender downwardly barbed bristles. (S. validus, I a/t/.) — Common every- 

 where in still fresh water. (Eu., Asia, etc.) 



H_ ^_ 4_ H- Culms slender from an annual root, terete, plano-convex or obtusely tri- 

 angular, naked ; the sheaths rarely bearing a short leaf; spikelets few or 

 several in a sessile cluster, sometimes solitary, much overtopped by the invo- 

 lucral leaf; bristles often few or wanting. 



10. S. debilis, Pursh. (PI. 3, fig. l -5.) Cidms obtusely triangular, with 

 .'«omewhat hollowed sides, 1-2° high, yellowish-green, shining ; spikelets 3 - 

 12, capitate, ovate-oblong, obtuse (3-4" long), chestnut-brown; involucral 

 leaf often horizontal at maturity ; scales roundish ; stamens 3 ; style 2-3 

 ^left ; bristles 6, stout, downwardly barbed, equalling or two surpassing the ob 

 ovate turgidly plano-convex (or bluntly 3-sided) abruptly mucronate-pointed 

 smoothish achene. — Swamps, Mass. to S. C, Minn, and Neb. Aug., Sept. 



11. S. Smithii, Gray. Culms terete, slender, 3-12' high, often leaf- 

 bearing from the upper sheatli, dull green as are the 1-3 oblong-ovate acute 

 spikelets ; involucral leaf always erect ; scales oblong-oval ; style 2-cleft ; 

 bristles 1 or 2 minute rudiments or none; a.Q\\en& somewhat lenticular, smooth. 

 deciduous with the scales. — Wet shores, Delaware Bay to L. Ontario, Mich., 

 N. Ind., and 111. July. 



12. S. SUpinus, L., var. Hallii, Gray. Cidms filiform, 5-12' high,, 

 upper sheath rarely distinctly leaf-bearing ; spikelets 1 - 7 in a sessile or some 

 times geminately proliferous cluster, ovate-oblong becoming cylindrical, green 



