GENUS 7. 



SEDGE FAMILY. 



24. Scirpus atrovirens Muhl. Dark-green 

 Bulrush. Fig. 824. 



Scirpus atroz'ircns Muhl. Gram. 43.- 1817. 



. georgianus Harper, Bull. Torr. Club 27 : 331. 1900. 



Perennial by slender rootstocks; culms triangular, 

 rather slender, leafy, 2-$ high. Leaves elongated, 

 more or less nodulose, rough on the margins, dark 

 green, 3 "-6" wide, one or two of them usually ex- 

 ceeding the inflorescence ; umbel i-2-compound or 

 simple; spikelets ovoid-oblong, acute, 2"-$" long, 

 densely capitate in 6's-2o's at the ends of the rays or 

 raylets ; involucels short ; scales greenish-brown, 

 ovate-oblong, acute, the midvein excurrent; bristles 

 usually 6, downwardly barbed above, naked below, 

 about as long as the achene, or shorter or wanting; 

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

 3-angled, pale brown, dull. 



In swamps. Nova Scotia to Saskatchewan, south to 

 Georgia and Louisiana. June-Aug. 



25. Scirpus pallidus (Britton) Fernald. 

 Pale Bulrush. Fig. 825. 



6". atrovirens pallidus Britton, Trans. N. Y. Acad. 

 Sci. 9:14. 1889. 



5". pallidus Fernald, Rhodora 8: 162. 1906. 



Perennial, the rootstocks short, stout ; culms 

 stout, triangular, 3-4 high. Leaves elon- 

 gated, pale, 3" -7" wide, somewhat nodulose; 

 umbel mostly compound ; spikelets oblong to 

 oblong-cylindric, numerous in very dense capi- 

 tate clusters; scales pale, ovate, acute, tipped 

 with an awn half as lon^ as the body; bristles 

 6, downwardly barbed, about as long as the 

 oblong, trigonous achene. 



Wet grounds, especially along streams, Mani- 

 toba to Nebraska, Kansas, Texas, Wyoming and 

 New Mexico. Reported from Minnesota. Summer. 



26. Scirpus microcarpus Presl. Small-fruited 

 Bulrush. Fig. 826. 



Scirpus microcarpus Presl. Rel. Haenk. i : 195. 1828. 

 Scirpus syli'aticus var. digynus Boeckl. Linnaea 36: 727. 



1870. 

 Scirpus rnbrotinctns Fernald, Rhodora 2: 20. 1900. 



Perennial, the culms 3-5 tall, often stout, over- 

 topped by the rough-margined leaves, the sheaths often 

 tinged with red. Longer leaves of the involucre usually 

 exceeding the inflorescence ; spikelets ovoid-oblong, 

 acute, ii"-2" long, 3-25 together in capitate clusters at 

 the ends of the usually spreading raylets; scales brown 

 with a green midvein, blunt or subacute ; bristles 4, 

 barbed downwardly nearly or quite to the base, some- 

 what longer than the achene; stamens 2; style 2-cleft; 

 achene oblong-obovate, nearly white, plano-convex or 

 with a low ridge on the back, pointed. 



In swamps and wet woods, Newfoundland to Alaska, 

 south to Connecticut, northern New York, Minnesota, Ne- 

 vada and California. July-Sept. 



