SIvDC.I- FAMILY. 



265 



10. Scirpus Americanus Pers. Three-square. Chair-iuakcr's Rush 



(Fig. 618.) 



Scirpus Americanus Pers. Syn. i: 68. 1805. 

 .SV/V/w f>iin_t; en .< Vahl, Enum, 2: 255. 1806. 



Perennial by long rootstocks, culms sharply tri- 

 angular with concave sides or one of the si<U-> 

 nearly flat, erect, stiff, i-4 tall. Leaves 1-3, 

 narrowly linear, keeled, shorter than the culm; 

 spikelets oblong-ovoid, acute, 4 // -6 // long, capitate 

 in clusters of 1-7, appearing as if lateral; involucral 

 leaf solitary, slender, i}4'-4' long; scales broadly 

 ovate, brown, often emarginate or sharply 2-cleft 

 at the apex, the midvein extended into a subulate 

 awn sometimes \" long, the margins scarious, 

 ciliolate or glabrous; bristles 2-6, downwardly 

 barbed, shorter than or equalling the achene; 

 stamens 3; style usually 2-cleft; achene obovate, 

 plano-convex, smooth, dark brown, mucronate. 



In fresh water and brackish swamps throughout 

 North America. Also in Chile. June-Sept. 



Scirpus Americanus longispicatus Britton, Trans. N. Y. Acad. Sci. n: 78. 1891. 

 Spikelets linear-cylindric, 5" -12" long; bristles as long as the broadly obovate achenr. South 



shore of Lake Ontario; Colorado and New Mexico. 



ii. Scirpus Olneyi A . i 



Bulrush, i Fig. 619.) 



Scirpus Olneyi A. Gray, Boat. Journ 5 jjj. 



1845. 



Similar to the preceeding species, perennial by long 

 stout rootstocks, culms stout, sharply 3-angled with 

 concave sides, 2-7 tall. Leaves 1-3, i'-5' long. 

 or sheaths sometimes leafless; spikelets capitate in 

 dense clusters of 5-12, oblong or i>v<>id-oblong. ob- 

 tuse, 2^ // -4 // long, the solitary involucral leaf hoct, 

 stout, erect, y*'-i}i' long; scales ovml or orbicular. 

 dark brown with a green midvein, emarginatc or mu- 

 cronulate, glabrous; bristles usually *>. -.lightly shorter 

 than or equalling the achene, downwardly barbed; 

 stamens 2-3; style 2-cleft; achene obovate, plano- 

 convex, brown, mucronate. 



In salt marshes, Rhode Maml t- Fl-.rida. Tr*a, 

 Mexico and California, extending north along the Padic 

 Coast to Oregon. Also in Arkansas. Jane-Sept 



12. Scirpus Torreyi Olney. Torrey's 

 Bulrush. (Fig. 620.) 



Scir/>us Torreyi Olney, Proc. Providence Frank. Soc. 



1:32. 1847. 



Perennial by short or slender rootstocks, culms 

 sharply 3-angled, rather slender, nodulose, 2-4 

 tall. Leaves narrowly linear, elongated, nodulose, 

 light green, sometimes overtopping the culm; 

 spikelets 1-4, in an apparently lateral capitate clus- 

 ter, oblong, narrowed at each end, 5 "-8" long; 

 involucral leaf 2 / -6 / long, erect; scales ovate 

 or lanceolate, shining, chestnut-brown, glabrous, 

 obtuse or the upper acute, mucronulate; bristles 

 about 6, downwardly barbed, longer than the 

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

 smooth, shining, light brown, 3-angled, one of its 

 sides broader and flatter than the others. 



In swamps, Vermont to Rhode Island and Pennsyl- 

 vania, west to Minnesota and Manitoba. July-Sept. 



