527 
cyperace^e. (sedge family.) 
plano-convex. — Our plant appears constantly to have a 2-cIefl style, 
and the scales often a little downy on the back, and is S. vilidus, 
Vahl., S. acutus, Muhl. — Fresh-water ponds and lakes. July._ 
Culm as thick as the finger at the base, tipped with an erect pointed 
involucral leaf, which is shorter or longer than the panicle. 
8- S. debilis, Pursh. Culms slender (6'-12' high), striate, 
tufted, from fibrous (annual?) roots, leafless, sometimes 1-leaved at 
the base ; spikes ovate, 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; achenium obovate, plano¬ 
convex or lenticular, shining, minutely dotted, shorter than the 4 - 6 
bristles. — Low grounds, and banks of streams, not rare. August. 
* * * Spikes clustered and mostly umbelled, manifestly terminal, many- 
flowered : involucre leafy: culm leafy, triangular, with closed joints 
below {style 3-cleft). 
**- Scales of the large spikes awn-pointed, lacerate-3-cleft at the apex. 
9. S. mariti inns, L. (Sea Club-rush.) Leaves flat, lin¬ 
ear, as long as the stout culm (1°- 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-orbicular , much compressed , 
flat on one side, convex or obtuse-angled on the other, minutely pointed , 
shining , longer than the 1 -6 unequal and deciduous (sometimes obso¬ 
lete) bristles. — Var. macrostachyos, Michx. (S. robustus, Pursh), is 
a larger form, with very thick oblong or cylindrical heads, becoming 
1' to 1£' long, and the longer leaf of the involucre often 1° long. — 
Salt marshes, common on the coast. Salt springs, Salina, New York. 
Aug. — Heads beset with the spreading and finally recurved short 
awns which abruptly tip the scales. 
10. S. flaiviatilis. (Great River Club-rush.) Leaves flat, 
broadly linear (£' or more wide), tapering gradually to a point, the up¬ 
per and those of the very long involucre very much exceeding the 
compound umbel; rays 5-9, elongated, recurved-spreading, bearing 1- 
5 ovate or oblong-cylindrical acute heads; achenium obovate, sharply 
and exactly triangular, conspicuously pointed , opaque, scarcely equal¬ 
ling the 6 rigid bristles. (S. marit., var. ? fluviatilis, Torr., excl. syn. 
Ell.) — Borders of lakes and large streams, W. New York to Michi¬ 
gan. July, Aug. — Culm very stout, sharply triangular, 3P-4° high. 
Leaves roughish 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 f' to 1£' long, paler and duller than in 
No. 9, the scales less lacerate and the awns less recurved; the fruit 
larger and very different. 
Scales of the small compound-umbelled and clustered heads awnless. 
11. S, atrovirens, Muhl. Culm rigid, obtusely triangular, very 
