202 MACOUN AND BURGESS ON 



stalked with narrower segments. Eootstock slender, wide-spreading, black ; stalks scat- 

 tered, slender, blackish at the base but brownish-yellow above naked except when very 

 young, and usually as long as or even longer than the fronds ; fronds erect, oblong- 

 lanceolate, but little narrowed at the base, 9 inches to 2 feet long by 3 to 6 inches wide, 

 short pointed, slightly pubescent along the midribs and veins, and pinnate ; pinnce short- 

 stalked, linear-lanceolate, acute or acuminate, mostly horizontal, and deeply pinnatifid ; 

 segments oblong-ovate, obtuse, and entire, the fertile ones with their margins revolute 

 often making them appear acute ; veins mostly forked ; sori small, often confluent, placed 

 midway between the midrib and margin or nearer the midrib ; indusia generally naked. 



Specimens of the Marsh-Fern are sometimes met with having the lower pinna; 

 reduced and seemingly intermediate between this species and A. Noveboracense the var. 

 intermedia of Lawson in Can. Nat., Vol. I, p. 284, and such specimens are often difficult to 

 place. The most obvious distinguishing characters in A. Noveboracense are : (1) stalk 

 much shorter than frond ; (2) frond acuminate and much contracted at the base ; (3) pin- 

 nae closely sessile ; (4) lobes flat ; (5) veins mostly simple ; (0) sori marginal and distinct. 

 The degree of pubescence and thickness of the fronds in this fern are also subject to con- 

 siderable variation, extremes in the direction of these characters constituting var. pubes- 

 cent of Prof. Lawson, while those in the reverse direction form var. glabra. Occasionally 

 plants are found with some of the segments crenate or toothed, and still more rarely fronds 

 are seen which are bipinnate with pinnatifid divisions. Forking fronds, too, are seen 

 in this fern from time to time. 



A very common fern in cedar, tamarack, and other swamps, extending, according to 

 Eaton, westward to Lake Winnipeg, which is also probably about its northern limit. 

 Quite common in swamps in Nova Scotia — Rev. E. H. Ball. Rather common in wet 

 marshy places in New Brunswick. — Fowler. Common in Quebec. — McCord, Provancher, 

 Maclagan, Parsons, etc. Abundant in Eastern and Central Ontario. — Macoun, Fletcher, 

 Billings, Maclagan, Logic, Burgess, etc. Muskoka aud Parry Sound, Ont. — Burgess. Near 

 Red River Settlement, Man. — McTavish. 



* * Fronds firmly membranaceous, often evergreen ; stalks and thickened root- 

 stocks chaffy ; veins forking freely. 



f Fronds large, pinnate with pinnatifid pinna? ; indusia large, thinish, flat, and 

 persistent. 



3.— A. cristatum, Swarlz, (Crested Wood-Fern), Syn. Fil., 52. Cray, Man., 665. 

 Provancher, Flor. Can., 118. Macoun's Cat., No. 2309. Fowler's N. B. Cat., No. 151. 

 Ball, Trans. N. S. Inst. Nat. Sci., IV, 153. Eaton, Ferns of N. A., II, 153. Underwood, 

 Our Nat. Ferns, etc., 106. 



A. Lancastriense, Spreng. 



Lastrea cristata, Presl , Lawson, Can. Nat. I, 282. 



Polypodia in cristatum, L. 



Polystichinn cristatum, Roth., Watt, Can. Nat., IV, 363. 



Nephrodiiim cristatum, Mx. 



A nearly evergreen species found in low woods and swamps, sometimes in dry 

 places, growing from 1 to 3 feet high. The fertile and sterile fronds are somewhat unlike. 



