Allosorus aquilinus, Presl, Tent Pterid., 153.
Is common, growing usually on sand or sandy loam, from the Atlantic to the Pacific. Very common in Nova Scotia. (McKay.) Growing everywhere in New Brunswick. (Fowler.) Prince Edward Island. (Bain.) Jupiter River, Anticosti, Que. (Macoun.) Common everywhere in Quebec. (McCord, St. Cyr.) Common at Lake Mis-tassini, and down the Rupert River to James Bay, N. E. Ter. (J. M. Macoun.) Common in Ontario and in parts of Manitoba. (Macoun, Burgess, etc.) Saskatchewan plains, N. W. Ter., and Rocky Mountains. (Macoun.)
Var. lanuginosa, Bong.; Hook., Fl. Bor. - Am., ii., 263. Macoun & Burgess, Trans. Roy. Soc. Can., ii., sect, iv., 187.
P. lanuginosa, Bory, in Willd., Sp. PL, v., 403.
The common form on Vancouver Island and the mainland of British Columbia, where it is known to extend eastward at least as far as the Columbia River at Donald. (Fletcher, Macoun.) It is characterized by the silky-pubescent under surface of the fronds.