526 CYPERACEJ2. (SEDGE FAMILY.) 
tension of the 1-leaved, involucre exactly like a continuation of the na¬ 
ked culm. 
Culm 3-angular, stout, chiefly from running rootstocks: spikes many- 
flowered, rusty brown, closely sessile in one cluster: sheaths at base 
more or less leaf-bearing. 
4. S. ptmgens, Vahl. Culm sharply 3-angled throughout (1° 
-4° high), with concave sides; leaves 1-3, elongated (4'- 10' long), 
keeled and channelled ; spikes 1-6, capitate, ovoid, long overtopped 
by the pointed involucral leaf; scales ovate, sparingly ciliate, 2-cleft 
at the apex and awl-pointed from between the acute lobes; anthers 
tipped with an awl-shaped minutely fringed appendage ; style 2-cleft} 
bristles 2 -6, shorter than the obovate plano-convex and mucronate 
smooth achenium. (S. triqu&ter, Michx ., not of L. S. Americanus, 
Pers.) — Borders of salt and fresh ponds and streams. July, Aug. — 
This is the species used for making rush-bottom chairs. 
5. S. Ollteyi, Gray. Culm 3-wing-angled, with deeply excavat¬ 
ed sides, stout (2°-7° high), the upper sheath bearing a short 3-angular 
leaf or none ; spikes 6 - 12, closely capitate, ovoid, obtuse, overtopped 
by the short involucral leaf; scales orbicular, smooth, the inconspic¬ 
uous mucronate point shorter than the scarious apex ; anthers with a 
very short and blunt minutely bearded tip ; style 2-cleft ; bristles 6, 
scarcely equalling the obovate plano-convex mucronate achenium. 
Salt marshes, Martha’s Vineyard, Oakes , Rhode Island, Olney, and 
New Jersey, Knieskem. July. — Cross section of the stem strongly 
3-rayed, with the sides parallel. — Much nearer than the last to the 
European 5. triqueter, which has similar anthers and an abbreviated 
or almost abortive leaf; but its culm is wingless, and the cluster of 
spikes compound, some of them umbellate-stalked. 
6. s. Torreyi, Olney. Culm 3-angled , with concave sides, 
rather slender (2° high), leafy at the base ; leaves 2-3, more than half 
the length of the culm, triangular-channelled, slender; spikes l-4j 
ovate-oblong, acute, distinct, sessile, long overtopped by the slender 
erect involucral leaf; scales ovate, smooth, entire, barely mucronate; 
style 3-cleft; bristles longer than the unequally triangular obovate very 
smooth and long-pointed achenium. (S. mucronktus, Pursh f Torr. F • 
N. Y.) — Borders of ponds, brackish and fresh, New England to 
Michigan. July, Aug. —S. mucronatus, L., should it ever be foun 
in the country, will be known by its leafless sheaths, conglomerate 
head of many spikes, stout involucral leaf bent to one side, ^ c * 
•*- Culm terete, naked. . 
7. S. lacustris, L. (Bulrush.) Culm large, cylindrical, 
gradually tapering at the apex (3°-8° high), the sheath bearing a 
small linear-awl-shaped leaf or none ; spikes ovate-oblong, numerous 
in a compound umbel-like panicle , turned to one side, rusty brown, 
scales ovate, mucronate; bristles 4-6; achenium obovate, mucronate, 
