186-1.] LAWSON ON CANADIAN FERNS. 299 



E. si/lvaticum, Linn. Newfoundland and New Brunswick, 

 Hook. Fl. Bor. Amer. 



U. sylvatlcum, i^. cajnllare. Much branched ; branches very 

 long straight, and exceedingly slender (capillary). Farmersville. 



E. umbrosum, Willd. Belmate. 



E. arvene, Linn. West from London, W. Saunders. The 

 rhizome bears large spherical pill-like modules, which are how- 

 ever more conspicuous in var. y3- granulatum. 



E. arvense, /3. granulatum. 



E. Telmatcja, Ehrhart. Shores of Lake Ontorio, Beck. 



E. Umosiun, Forics. — The great value of this species and of 

 E. arvense as fodder-plants, is confirmed. On the western prairies 

 horses are said to get " rolling fat " on equisetum in ten days; 

 and experienced travellers tell me, that their horses always go 

 faster next day after resting at nia;ht on equisetum pasture. The 

 horses do not take to it at first ; but after having a bit of equise- 

 tum put occasionally into their mouths, they soon acquire a 

 liking for it, and prefer it to all other herbage. Near Komoka, 

 W. Saunders. 



E. Jii/emale, Linn. Lake Huron, Hook. Fl. Bor. Am. ; St. 

 Joachim, Abbe Provancher ; London, W. S. 



E. rohustum, Braun. Stems much thicker than in E. liyemale^ 

 the ridues with one line of tubercles; sheaths shorter than broad, 

 with a black band at base, and a less distinct one at the margin ; 

 teeth about forty, three-keeled. E. rohustum, Braun. A. Gray. 

 Grenadier Pond, on the Humber River near Toronto, 3d June 

 1862. It is difficult to decide whether this and other forms are 

 redly distinct from E. liyemale ; certainly that species varies in 

 size, in roughness, and in other characters. In E. rohustum the 

 teeth are twice as many as in E. hyemale, but even this is perhaps 

 not a constant character. 



E. variegatum, Weber and Mohr. ; St. Joachim, Abbe Pro- 

 vancher. 



E. scirpoides, Michaux. 



E. scirpoides, ^. minor. 



E. j^alustre, Linn. — " Canada, from Lake Huron, Dr. Todd, 

 Mr. Cleghorn, Mrs. Perceval, to the shores of the xlrctic Sea, Dr. 

 Richardson, Drummond, Sir John Franklin, Captain Back." — 

 Hook. Fl. Bor. Amer. — Professor A. Gray speaks of " the Euro- 

 pean E. palustre," attributed to this country (the N. American 

 States) by Pursh, probably incorrectly." Dr. Hooker indicates its 



