'GENUS 7. 



12. Scirpus mucronatus L. 

 Fig. 812. 



SEDGE FAMILY. 



Bog Bulrush. 



Scirpus mucronatus L. Sp. PI. 50. 1/53. 



Perennial, culms stout, somewhat tufted, sharply 

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

 capitate cluster, oblong, obtuse, many-flowered, 4"-o." 

 long, rather more than i" in diameter, subtended by 

 the solitary linear abruptly spreading involucral leaf; 

 scales broadly ovate, obtuse, light brown with a nar- 

 row green midvein, mucronate ; bristles 6, stout, 

 rigid, downwardly barbed, as long as the achene; 

 stamens 3; style 3-cleft; achene obovoid, smooth, 

 shining, dark brown, 3-angled, two of the sides nar- 

 rower and more convex than the third. 



In a swamp in Delaware county, Pennsylvania. Prob- 

 ably adventive or fugitive from Europe. Widely distrib- 

 uted in the Old World. July-Sept. 



13. Scirpus etuberculatus (Steud.) Kuntze. Canby's Bulrush. Fig. 813. 



Scirpus maritimus var. cylindricus Torr. Ann. Lye. N. Y. 



3: 325. 1836. 

 Rhynchospora etuberculata Steud. Syn. PI. Cyp. 143. 



S. Canbyi A. Gray, Am. Journ. Sci. (II.) 38 : 289. 1864. 



S. etuberculatus Kuntze, Rev. Gen. PI. 758. 1891. 



S. cylindricus Britton, Trans. N. Y. Acad. Sci. n : 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 apparently lateral simple or 

 compound umbel, drooping, oblong-cylindric, acutish, 

 6"-io" long; primary rays of the umbel i'~4' 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 ; stamens 3 ; 

 style 3-cleft; achene obovoid, 3-angled, light brown, 

 smooth, abruptly subulate-pointed. 



In ponds and swamps, Maryland to Florida and Louis- 

 iana, mostly near the coast. Pole or Pool-rush. July- 

 Sept. 



14. Scirpus validus Vahl. American Great 

 Bulrush. Mat-rush. Fig. 814. 



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



Perennial by stout rootstocks, culm stout, terete, 

 smooth, erect, 3-9 tall, sometimes nearly i' in diam- 

 eter, sheathed below, the upper sheath occasionally ex- 

 tended into a short leaf. Involucral leaf solitary, erect, 

 shorter than the umbel, appearing as if continuing the 

 culm ; umbel compound, appearing lateral, its primary 

 rays slender, spreading, J'-2i' long, bracts linear-lanceo- 

 late, pubescent ; spikelets oblong-conic, sessile or some 

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

 or acute, 2^"-6" long, ii"-2" in diameter; scales ovate 

 to suborbicular, slightly pubescent, 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- 

 convex, obovate, nearly as long as the scale, gray to 

 brown, abruptly mucronate, a little more than ii' wide. 



In ponds and swamps, throughout North America, except the extreme north, and in thg West 

 Indies. The Old World S. lacustris L., with which our plant has been confused, has a 3-cleft style. 

 Black-rush. Bolder or Boulder Bast. Tule. June-Sept. 



