580 CYPERACEiE. (SEDGE FAMILY.) 



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

 — lu a siiigle locality in Delaware Co., Feim. ; probably iutroduced from 8. 

 Europe. 



-I- -i- Culm triangular, tall and stout, from slender running rootstocks ; spikelets 

 manij-Jiowered, loosely umbellate or corymbed, involucellate-br acted. 



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

 above, obtusely below, the sheath at base exteuded iuto a loug sleuder ti-ian- 

 gular aud channelled leaf (2-4° long) ; involucral leaf similar (4-8' loug), 

 continuing the culm; spikelets oblong (4-6" loug), single or souietimes pro- 

 liferously 2 or 3 together, noddiug on the apex of 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, furuished 

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

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

 Salisbury, Md. 



^_ H_ ^_ 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, 

 scale4ike and rusty-scarious ; scales of the spikelets rusty or cliestnut-broan, 

 scarious, the midrib extended into a mucronate point. 



9. S. laciistris, L. (Great Bulrush.) Culm 3-9° high, i-i' tliick 

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

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

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

 sleuder downwardly barbed bristles. (S. validus, Fahl.) — Common every- 

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



^_ ^_ H_ 4_ 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. 1 -5.) Culms 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 tlie upper sheath, dull green as are the I -3 oblong-ovate acute 

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

 bristles 1 or 2 minute rudiments or none; achene somewhat lenticular, smooth, 

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

 N. Ind., aud 111. July. 



12. S. supinus, L., var. Hallii, Gray. Culms f I if orm, 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 



