268 



CYPERACEAE. 



ig. Scirpus robustus Pursh. Salt Marsh Bulrush. (Fig. 627.) 



Scirpus robustus Pursh, Fl. Am. Sept. 56. 1814. 

 Scirpus maritimus var. macrostachyiis Michx. Fl. 



Bor. Am. i: 32. 1803. Not S. inacrostachyns Lam. 



Perennial by large rootstocks, culm stout, stiff, 

 sharply 3-angled with flat sides, smooth, 2-5 

 tall. Leaves equalling or overtopping the culm, 

 dark green, smooth, -2%"-^' wide, the midvein 

 prominent; involucral leaves 2-4, elongated, erect, 

 similar to those of the culm, often i' long; spike- 

 lets ovoid-oblong, obtuse or subacute, stout, 8 // -i2 // 

 long, 4 // ~5 // in diameter, 6-20 together in a dense 

 often compound terminal cluster; scales ovate, 

 brown, puberulent, thin, lacerate or 2-toothed at 

 the apex, the midvein excurrent into an, at length, 

 reflexed awn iK // ~ 2 X // l n g; bristles 1-6, fragile, 

 shorter than the achene or none; stamens 3; style 

 3-cleft; achene compressed, very flat on the face, 

 convex or with low ridge on the back, obovate- 

 orbicular, dark brown, shining, iJ^'Mong. 



In salt marshes, Nova Scotia to Texas. July-Oct. 

 20. Scirpus fluviatilis (Torr. ) A. Gray. River Bulrush. (Fig. 628.) 



Scirpus maritimus var. fliiz'iatilis Torr. Ann. Lye. N. 



Y. 3: 324. 18.36. 

 Scirpus fiuriatilis A. Gray, Man. 527. 1848. 



Perennial by large rootstocks, culm stout, smooth, 

 sharply triangular with nearly flat sides, 3-6 tall. 

 Leaves 4 // -8 // wide, smooth, equalling or overtopping 

 the culm, attenuate to a very long tip, the midvein 

 prominent; those of the involucre 3-5, erect or spread- 

 ing, some of them 5 / -io / long; spikelets in a terminal 

 umbel, solitary, or 2-3 together at the ends of its long 

 spreading or drooping rays, or the central spikelets 

 sessile, oblong-cylindric, acute, 8 // -i2 // long, about 

 3X" in diameter; scales ovate, scarious, puberulent, 

 the midvein excurrent into a curved awn i^ // -2 // 

 long; bristles 6, rigid, downwardly barbed, about as 

 long as the achene; style 3-cleft; achene sharply 

 3-angled, obovoid, rather dull, short-pointed, i" long. 



In shallow water along lakes and streams, Quebec to 

 Minnesota, New Jersey, Illinois and Kansas. June-Sept. 



21. Scirpus sylvaticus L. Wood Bulrush. (Fig. 629.) 



Scirpus sylvaticus L- Sp. PI. 51. i"53- 



Perennial by long rootstocks, culm triangular, 

 stout, smooth, 4-6 tall, often overtopped by the 

 upper leaves. Leaves flat, 5 // -8 // wide, rough on 

 the margins, more or less rugulose, the midveiu 

 prominent, those of the involucre 5-8, the larger 

 similar to those of the culm and often i long or 

 more; umbel terminal, very large, sometimes v 

 broad, about 3 times compound, the spikelets ovoid 

 or ovoid-oblong, mostly acute, i>^ // -2^ // long, 

 borne in capitate clusters of 2-8 at the ends of the 

 raylets; bractlets of the involucels small, scarious, 

 linear or lanceolate; scales ovate-oblong, obtuse, 

 brown with a green centre; bristles 6, downwardly 

 barbed, slightly exceeding the achene; stamens 3; 

 style 3-cleft; achene oblong, 3-angled, obtuse, 

 nearly white, mucronulate, not shining. 



In swamps, Massachusetts to North Carolina. Also 

 in Europe. June-Aug. 



