CRYPTOGAMIA— FILICES. Equisetum. 339 



In spongy watery bogs not uncommon. 



Perennial. June, July. 



6'^em rather slender, deeply furrowed, beset throughout with whorls 

 of slender, ascending, deeply furrowed, angular, minutely rough 

 branches, whose joints are each crowned with a small deeplv- 

 toothed sheath, often paler than in the foregoing. The terminal 

 catkin, always solitary, at the top of the frond, most essentially 

 distinguishes this species from E. arvense, agreeing so far with 

 the following, but is more slender and cylindrical than either. 



The variety /3 I have not examined ; the y is similar to what oc- 

 curs in E. limosum, confounded with the present by Huller. 



5. E. ihnosiun. Smooth Naked Horsetail. 



Stem partially naked, striated, smooth as well as tlie 

 branches. Catkin terminal, elliptical. 



E. limosum. Linn. Sp. PI. 1517. Willd. v. 5. 4. Fl. Br. 1 105 

 En^l. Bot.v. 13. ^.929. Hook. Scot. p. 2. 161. Bolt. Fil. 68. 

 <. 38. 



E. fluviatile. Fl. Dan. t. 1 1S4. Ehrh. Criipt. 41. PI. Off. 290. 



E. n. 1677/3. Hall. Hist. v. 3.2. 



E. nudum Isevius nostras. Raii Sijn. 131. t. 5./. 2, a, b. 



In marshy watery places frequent. 



Perennial. June, July. 



Stems stouter than the last, about two feet high, very smooth to 

 the touch, though finely striated, not deeply furrowed ; either 

 quite simple, or more usually furnished, in the upper part, with 

 several simple, ascending, shortish //ra/zc/it'i, striated and smooth 

 like the stem. Sheaths rather short, with many short brown 

 teeth. Catkin large, elliptical, bluntish. 



One Swiss specimen, from Mr. Davall, has a small catkin at the 

 summit of each branch of the three uppermost whorU, resem- 

 bling the variety of E. palustre, represented bv Dillenius in 

 Ray's Synopsis, t. ti.f. 3 ; hut the stem is not dee])ly furrowed, 

 as in that figure, which by this character is identified with E. pa- 

 lustre. I have seen no such variety of E. limosum in England. 



6. E. hycmale. Greater Rough Horsetaih Shave- 



grass. 



Stem naked, very rough, mostly branching at the base. 

 SIrjiiIis whitish ; black at the top and bottom ; teeth 

 decitluous. Catkin terminal. 



E. hyemale. Lmn. Sp. PI. ]:>\7. U'dhl. v. 5. S. /7. Br. I IOj. 



En<il. Bot. V. 13. /. 915. Ihnk. Scot. p. 2. 161. Lond. t. 161. 



Li^hff. 6.-)0. Ehrh. Crypt. j\. 

 E. n. 1679. //'///, Hist, r.3,3. 



z 2 



