2 66 CYPERACEAE. 



^-r^y 



13. Scirpus mucronatus L. Bog Bulrush. 

 (Fig. 621.) 



Scirpus mucronatus L. Sp. PI. 50. 1753. 



Perennial, culms stout, somewhat tufted, sharp! y 

 3-angled, smooth, i-3 tall. Spikelets 5-12 iii a 

 capitate cluster, oblong, obtuse, many-flowered, 

 4 r/ ~9 // long, rather more than i " in diameter, sub- 

 tended by the solitary linear abruptly spreading in- 

 volucral leaf; scales broadly ovate, obtuse, light 

 brown with a narrow green midvein, mucronate; 

 bristles 6, stout, rigid, downwardly barbed, as long- 

 as the achene; stamens 3; style 3-cleft; achene ob- 

 ovoid, smooth, shining, dark brown, 3-angled, two- 

 of the sides narrower and more convex than the 

 third. 



In a swamp in Delaware county, Pennsylvania. 

 Probably adventive or fugitive from Europe. Widely- 

 distributed in the Old World. July-Sept. 



14. Scirpus cylindricus (Torr. ) Britton. Canby's Bulrush. (Fig. 622.) 



Scirpus maritimus var. cvlindricus Torr. Ann. 



Lye. N. Y. 3: 325. 1836. 



Scirpus leptolepis Chapm. Fl. S. States, 520. 1860. 

 Scirpus Canbyi A. Gray, Am. Journ. Sci. (II.) 38: 



289. 1864. 

 Scirpus cylindricus Britton, Trans. N. Y. Acad. Sci. 



II: 79. 1892. 



Perennial by stout rootstocks. culm stout, 

 sharply 3-angled above, 3-6 high, the linear 

 nodulose keeled and channeled dark green 

 leaves nearly or quite as long. Involucral leaf 

 solitary, 4/-io' long, erect; spikelets in an appa- 

 rently lateral simple or compound umbel, droop- 

 ing, oblong-cylindric, acutish, 6"-io" long; 

 primary rays of the umbel \'-\ f long, bracted 

 by i or more subulate-linear leaves; scales ovate 

 or ovate-lanceolate, pale brown with scarious 

 margins, acute, mucronulate; bristles 6, stout, 

 rigid, about as long as the achene, serrate; sta- 

 mens 3; style 3-cleft; achene obovoid, 3-angled, 

 light brown, smooth, abruptly subulaterpointed. 



In ponds and swamps, Maryland to Florida and Louisiana, mostly near the coast. July-Sept. 



15. Scirpus lacustris L,. Great Bulrush. Mat-rush. (Fig. 623.) 



Scirpus lacuslris L. Sp. PI. 48. 1753. 

 Scirpus validus Vahl, Enum. 2: 268. 1806. 



Perennial by stout rootstocks, culm stout, terete, 

 smooth, erect, 3-9 tall, sometimes nearly V in di- 

 ameter, sheathed below, the upper sheath occasion- 

 ally extended into a short leaf. Involucral leaf soli- 

 tan,', erect, shorter than the umbel, appearing as if 

 continuing the culm; umbel compound, appearing 

 lateral, its primary rays slender, spreading, i'-4' 

 long, bracts linear-lanceolate, scarious; spikelets ob- 

 long-conic, becoming oblong-cylindric, sessile or some 

 of them peduncled, in capitate clusters of 1-5, obtuse 

 or acute, 2-"-S" long, \Y^'-i" in diameter; scales 

 ovate or oblong, with a rather strong midvein which 

 is sometimes excurrent into a short tip; bristles 4-6, 

 downwardly barbed, equalling or longer than the 

 achene ; stamens 3 ; style 2-cleft; achene plano-con- 

 vex, obovate, gray, abruptly mucronate, dull. 

 In ponds and swamps, throughout North America. Also in the Old World. June-Sept 



