446 ACOTYLEDONOUS PLANTS. 



HAB. Swamps. Arc. Amer. to Vir. May, June. 11. Stem* 

 12 18 inches high, deeply sulcate and roughish ; branches 

 whorled and nearly erect. Spike an inch long, slender and 

 blackish. 



2. E. sylvaticum Linn. : branches of both the fertile and sterile stemi 

 compound, scabrous, curved downwards, 3- or 4-sided ; sheath sloose, 

 deeply cleft into membranous segments. 



HAB. Low grounds. N. S. N. to Arc. Amer. May. If. 

 Stems 12-18 inches high. Well characterized by its 4 or 5 

 whorls of compound branches. 



3. JB. hyemale Linn. : stems all simple, erect, very rough, naked, 

 bearing spikes at the apex ; sheaths short, whitish, black at the base 

 and apex ; teeth awned, at length caducous. 



UAB. Woods and marshes. Can. and N. S. W. to Miss. Junp, 

 July. If- Stems simple, 1 2 feet high, naked, furrowed, 

 terminating in an oval head. Skcatfis nearly equidistant, about 

 2 inches apart. Scouring -Ruth. 



4. E. limosum Linn. : stems branched upwards, (sometimes simple;) 

 branches simple, short, 5-sided, smooth ; spike oblong or ovate ; 

 sheaths appressed. E. uUginosum Wttld. Pursh. 



"HAB. Borders of swamps. N. S. July. If. Stems 2 3 feet 

 high, erect, simple or with a few whorls of branches at the top. 

 S/tetUhs numerous, short, with 15 20 narrow acute teeth. Spikt 

 brown, scarcely an inch long. 



5. E.fluxiatile Linn. : sterile stems branching, somewhat scabrous ; 

 branches numerous, angled ; fertile ones with broad sheaths ; teeth 

 long, cuspidate. E. telmateia Ehrh. . . 



HAB. Buffalo, N. Y., and the shores of Lake Superior. Torr. 

 H. Fertile stems appearing first, a foot high. Sterile stems 2 5 

 feet high, with numerous joints and many long verticillate 

 branches. Spike oblong. 



6. E. arcense Linn. : sterile stems somewhat decumbent, with simple, 

 square and scabrous branches ; fertile ones erect, simple ; sheaths in- 

 cisely toothed, cylindrical ; teeth acute. 



HAB. . Moist grounds. N. S. N. to Arc. Amer. April, May. 

 It. Fertile stems appearing first, 6 8 inches high, with large 

 ovate brownish spikes. Sheaths 3 5, swelling, whitish at base, 

 ending in 68 long acute teeth. Sterile stems a foot or more 

 high, jointed, with whorls of ascending branches, which are 3 

 or 4-cornered. 



7. E. variegatum Smith : cespitose ; stems somewhat branched at 

 base, naked, filiform, scabrous, bearing a blackish spike at the top ; 

 sheaths 3- toothed, blackish; teeth membranaceous, lanceolate, whitish, 

 deciduous at the tips. E. scirpoides Mich. Pursh. 



HAB. Woods on high grounds. Can. and N. S. N. to Arc. 

 Amer. July. If. Stems 36 inches high, many from the 

 same root, simple, filiform, 5-sided. Spike small, ovate, black- 

 ish. Our plant differs in no respect from the foreign, except in 

 its smaller size. 



