CYPERACE^. (SEDGE FAMILY.) 563 



. downwardly barbed bristles. (S. acutus, MuM. S. laciistris, of Amer. authors and 

 in former editions.) Common everywhere in still fresh water. Achenium 

 (I" long, half the size of that of the European S. lacustris, also narrower, pale, 

 not shining. A slender variety with narrower heads, very smooth scales, 

 and shorter or fragile bristles, was sparingly collected by Rev. J. W. Chickering 

 at Havana, New York. 



11. S. riparius, PresL, which largely takes the place of the preceding 

 south westward, probably within our limits, is known by the 2-4 rather shorter 

 and linear plumose scales, rather than bristles,of the perianth. 



*--*- H- -t- Culms slender from an annual root, terete, plano-convex or obtusely trian- 

 gular, naked; the sheaths at the base rarely extended into a short leaf: spikes 

 few or several, sometimes solitary, in a sessile cluster, much overtopped by the 

 involucral leaf: bristles of the perianth often few or wanting. 



12. S. debilis, Pursh. Culms obtusely triangular, with somewhat hol- 

 lowed sides, l-2 high, yellowish-green; spikes 3-12, capitate, ovate-oblong, 

 obtuse (3" -4" long), chestnut-brown; involucral leaf often horizontal at matu- 

 rity ; scales roundish ; stamens 3 ; style 2-3-cleft ; bristles 6, stout, downwardly 

 barbed, equalling or two surpassing the obovate turgidly plano-convex (or 

 bluntly 3-sided) abruptly mucronate-pointed smoothish achenium. (S. juncoi- 

 des, Roxburgh.) Swamps, Mass, to Virginia and southward. Aug., Sept. 



13. S. Smithii, n. sp. Culms terete, slender, 3' -12' high, often leaf-bear- 

 ing from the upper sheath, dull green as are the 13 oblong-ovate acute spikes ; 

 involucral leaf always erect ; scales oblong-oval ; style 2-cleft ; bristles 1 or 2 

 minute rudiments or none; achenium somewhat lenticular, smooth, deciduous 

 with the scales. (S. debilis, Gray, Gram, fr Cyp. 135.) Wet shores, Lake On- 

 tario to Illinois and Delaware Bay (in tidal mud). July. Named for C. E. 

 Smith, who indicated and insisted on its distinctions. 



14. S. supinus, L., var. Hallii. Culms filiform, 5' -12' high;* upper 

 sheath rarely distinctly leaf-bearing ; spikes 1 - 7 in a sessile or sometimes gem- 

 inately proliferous cluster, ovate-oblong becoming cylindrical, greenish ; scales 

 ovate, strongly keeled, mucronate-pointed; stamens 2; style 2-cleft; bristles 

 none ; achenium obovate-orbicular, mucronate, plano-convex, strongly wrinkled 

 transversely. (S. Hallii, Gray, addend, ed. 2.) Wet shores, Illinois, E. Hall, 

 &c., and southwestward. In Texas occurs the normal S. supinus, with 3-cleft 

 style and triangular achenium, as in Europe, where it sometimes has short 

 bristles, as in No. 13. (Eu.) 



* * * Spikes clustered in simple or mostly compound umbellate or cymose-panicled 

 dusters, many-flowered, terete: involucre of mostly several obvious and flat leaves : 

 culm tall, from tufted or running rootstocks ; triangular, leafy, sedge-like: styk 

 mostly 3-cleft. 



1- Spikes large, 6" - 1 5" long : midrib of the scales extended beyond the mostly lacerate 

 or two-cleft apex into a distinct awn. 



15. S. maritimus, L. (SEA CLUB-RUSH.) Leaves flat, linear, as long 

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

 spikes few -several in a sessile cluster, and often also with 1 -4 unequal rays 

 bearing 1-7 ovate or oblong-cylindrical (rusty-brown) spikes; awns of the 



