216 MA^OUN AND BURGESS ON 



taller and more common than the latter, which are non-leaf-like and remain erect, though 

 drying up, through the winter. Rootstock elongated, creeping, naked ; stalks scattered, 

 very sparingly chaffy and darkened at the hase, green above when fresh but brownish when 

 dry, the sterile usually a little longer than their fronds, the fertile usually much longer ; 

 sterile fronds foliaceous, smooth, triangular-ovate in outline, 3 to 15 inches in length, deeply 

 pinnatifid into oblong-lanceolate, generally obtuse, eutire, undulate or sinnuate-pinnatifid 

 segments, which are connected by a wing gradually widening upward, or the lowest pair 

 sometimes distinct ; fertile fronds nearly black, rigid, much contracted, bipinnate with the 

 erect, appressed, narrow pinnae divided into pinnules, which are rolled into berry-like 

 closed involucres ; veins of the sterile fronds copiously anastomosing, those of the fertile free. 



This fern is subject to considerable variation as regards its size and the cutting of its 

 pinna 1 and folding of their segments. All possible forms intermediate between the typical 

 sterile and fertile fronds may occur, and var. oblusilobata, Torr., (Onoclea obtusilobata, Schk.), 

 is the one standing about midway between the two. In it the pinna? of some of the sterile 

 fronds are again pinnatifid, and the so-formed pinnules becoming contracted and some- 

 what revolute, without entirely losing their foliaceous character, bear a few sori. This 

 form is often produced from rootstocks which bear normal sterile fronds also, and the same 

 plant may produce var. obtusilobata one year and the type form the next, — a plant with 

 bipinnate sterile fronds, thus standing between the normal sterile frond and var. obtusilobata, 

 is var. bipinnata, Lawson in Can. Nat., Vol. I, p. 274. Mr. McCord, in the same volume, 

 p. 356, mentions a form with glandular sterile fronds. 



Common throughout every part of Canada westward (in the swampy and wooded 

 region) to the head of Lake Wiunipegosis and the Saskatchewan. Only two stations are 

 recorded with us for var. obtusilobata, viz., wet meadow one mile north of Murray Town 

 Hall, Northumberland Co., Out. — Macoun, and Ottawa, Ont. — J. Fletcher; but there is little 

 doubt that a careful search would show it to be much more common. 



2. — 0. Struthiopteeis, Hoff., (Ostrich-Fern), Swartz, Syn. Fil., 111. Watt, Can. Nat., 

 IV, 363. Eaton, Ferns of N. A., II, 201. Underwood, Our Nat. Ferns, etc., 109. 



O. nodulosa, Schkuhr. 



O. Germanica, Hook. 



Osmunda Struthiopteris, L. 



Struthiopteris Germanica, Willd., Hook., Fl. Bor.-Am., II, 262. Gray, Man.. 66*7. Pro- 

 vancher, Fl. Cam, 717. Macoun's Cat., No. 2320. Fowler's N. B. Cat., No. 763. Ball, 

 Trans. N. S. Inst. Nat. Sci., IV, 154. Lawson, Can. Nat., I, 273, as var. Pennsylvanica. 



Struthiopteris Pennsylvanica, "Willd, Pursh, II, 666. 



A tall and showy species growing in large tufts, commonly 1J to 6 feet high, in low, 

 open or wooded, especially alluvial, ground. The barren and fertile fronds are quite dif- 

 ferent. The former, which are leaf-like, nmeh the taller, and non-evergreen, grow in a 

 circle and curve outward to form a beautiful vase-like receptacle for the latter, which are 

 few in number, non-leaf-like, and remain erect, though drying up, long after the sterile 

 have vanished. lJootstoek short, thick, erect, covered with old stalk-bases, giving off 

 long, slender, subterranean stolons; stalks short, stout, angular, those of the fertile fronds 

 a little the longest, darkened and chaffy at the base, green above when fresh but brown 

 when dry ; sterile fronds broadly-lanceolate, 1^ to 5 feet long, abruptly short-pointed, 



