134 OUR NATIVE FERNS AND THEIR ALLIES. 



5. E. palustre L. Stems slender, 10' 18' high, very deep- 

 ly $ 9 grooved, the grooves separated by narrow, wing like 

 ridges, roughish ; sheaths with about 8 lance-awl-shaped, whit- 

 ish margined teeth; branches few in a whorl, with mostly 5- 

 toothed sheaths. (E. pratense Reichenb.) Western New York 

 and Wisconsin to British Columbia and northward. 



6. E. litorale Kuhl. Stems slightly roughened, 6 19 

 grooved, the carinse convex ; sheaths sensibly dilated above, the 

 uppermost bell-shaped; leaves convex, angled beneath, sepa- 

 rate at the commisural groove ; teeth herbaceous, membranous 

 at the margin, narrow, lanceolate ; branches of two kinds, the 

 4-angled hollow, the 3-angled solid, first joint a little longer or 

 shorter than the sheath of the stem ; spores abortive, elaters 

 usually wanting. Bay of Quinte, Canada (Macouri); Vermont 

 (Pr ingle); Oswego River, New York ( Wibbe). 



ft Sheaths appressed. 



7. E. limosum L. Stems 2 3 high, slightly many-fur- 

 rowed, smooth, usually producing upright branches after fruc- 

 tification ; sheaths appressed, with about 18 dark-brown, short, 

 acute, rigid teeth ; air-cavities wanting under the grooves, small 

 under the ridges. Includes E. fluviatile L. (E. uliginosurn 

 Muhl., E. heleocharis Ehrh.) Virginia to Washington Terri- 

 tory and northward. 



2. HlPPOCH^ETE. Stems perennial, evergreen; spikes tipped 

 with a rigid point ; stoinata_ in regular JT&W_SJ fruiting in 

 summer. 



* Stems tall and stout, usually many-grooved. 

 t Branches numerous, regularly ivhorled. 



8. E. ramosissimum Desf. Stems grooved, more or less 

 roughened, 6 26 furrowed ; sheaths dilated, toothed ; teeth 

 not grooved, persistent or deciduous, leaving only a triangular, 

 very rarely a truncated margin ; leaves more or less distinct, 

 3 4 carinate ; branches when present, 4 9 angled ; series of 

 stomata in i 4 lines; inner bark of ridges higher than the 

 grooves ; ridges convex, marked with bands, never with two- 

 rowed tubercles. Cuba (Wright}, Mexico (Schaffner), British 

 Columbia (Lyall), and probably will be found in the intervening 

 territory-. 



