500 



CYPERACE^. (sedge FAMILY.) 



obovate, mucronate, plano-convex. — Our plant appears constantly to have a 2> 

 cleft style, and the scales often a little downy on the back, and is S. validas, Vahl, 

 & S. acutus, Muhl. — Fresh-water ponds and lakes; common. July. — Culm 

 as thick as the finger at the base, tipped with an erect and pointed involucral 

 leaf, which is shSl-ter or longer than the panicle. (Eu.) 



8. S. dcbilis, Pursh. Culms slender (6'- 12' high), striate, tufted, from 

 fibrous roots, leafless, or 1 -leaved at the base ; spikes mate, few (1-8) in a sessile 

 cluster, appearing deeply lateral by the prolongation of the 1 -leaved involucre ; 

 scales round-ovate (greenish-yellow) ; style 2 - 3-cleft ; bristles 4-6, longer than 

 the obovate plano-convex or lenticular shining minutely dotted achenium, or 

 rarely obsolete. ® — Low banks of streams, Massachusetts to Michigan, Illi- 

 nois, and southward. Aug. 



* * * Spikes clustered and mostly umbeUed, plainly terminal, many-flowered : involu- 

 cre leafy : culm leafy, triangular, and with closed joints below {style Z-cleft). 

 ■*- Scales of the large spikes awl-pointed, lacerate-3-clefl at the apex. 



9. S. maritimiis, L. (Sea Clue-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 1-3 ovate or oblong-cylindrical (rusty brown) spikes ; achenium obovate- 

 orbictdar, muck compressed, fiat on one side, convex or obtuse-angled on the othei-, mi- 

 nutely pointed, shining, longer than the I -6 unequal and deciduous (sometimes 

 obsolete) bristles. ^yar. MAOKOSTiOHYOS, Michx. (S. robdstus, Pursh.) is a 

 larger form, with very thick oblong or cylindrical heads, becoming I'-l^' long, 

 and the longer leaf of the involucre often 1° long. — Salt marshes ; common on 

 the coast, and near salt springs (Salina, New York), &o. Aug. — Heads beset 

 with the spreading or recurved short awns which abruptly tip the scales. (Eu.) 



10. S. fluvia.tilis> (Ritee Club-Rush.) Leaves flat, broadly linear 

 (J' or more wide), tapering gradually to a point, the upper and those of the vei-y 

 long involucre very much exceeding the compound umbel ; rays 5-9, elongated, 

 recurved-spreading, bearing 1-5 ovate or oblong-cylindrical acute heads ; acheni- 

 um obovate, sharply and exactly triangular, conspicuously pointed, opaque, scarcely 

 equalling the 6 rigid bristles. (S. marit., var. ? fluviatilis, Torr., excl. syn. Ell.) 

 — Bordei-s of lakes and large streams, W. New York to Wisconsin and Illinois. 

 July, Aug. — Culm very stout, sharply triangular, 3° - 4° high. Leaves rough- 

 ish on the margin, like the last; those of the umbel 3-7, the largest l°-2° 

 long. Principal rays of the umbel 3' - 4' long, sheathed at the base. Heads |' 

 to 1^' long, p."iler and duller than in No. 9 ; the scales less lacerate and the awns 

 less recurved ; the fruit larger and very dififerent. 



^- -1- Scales of tlte small compound-umbelled and clustered heads mucronate-tipped. 



11. S. sylvsitiCUS, L. Culm leafy (2° -5° high); leaves broadly linear, 

 flat, rough on the edges; umbel cymose-decompound, irregular ; the numerous 

 spikes clustered (3 - 10 together) in dense heads, ovoid, dark lead-colored or olive- 

 green turning brownish; bristles 6, downwardly barbed their whole length, straight, 

 scarcely longer than the convex-triangular achenium. — Low grounds, N. New 

 England and northward. — Var. ate6tikens (S. atrovirens, il/ij/i?.) is a form 

 with the spikes (10-30 together) conglomerate into denser larger heads. — Wet 



