FILICES. 39 



scales, which are toothed on the margins. Fronds petiolate, coriaceous, 

 evergreen, not scurfy, glabrous when full grown, strap-shaped or 

 oblong-strapshaped or lanceolate- or ovate-oblong, acuminate at the 

 apex, abrupt at the base, very deeply pinnatipartite ; segments strap- 

 shaped or lanceolate, with broad adnate bases, usually indistinctly 

 crenate or serrate, more rarely deeply crenate or serrate or pinnatifid. 

 Secondary veins forked, or with 1 to 4 alternate lateral veins below 

 the terminal fork, the ultimate veins not reaching the margin. Sori 

 round or roundish, arranged in a line on each side of the segment, and 

 about midway between it and the margin, attached to the extremity 

 of the first anterior branches of the secondary veins. No barren 

 fronds differing in shape or division from the fertile fronds. 



Yar. a. genuinum. 



Stipes containing a single vascular bundle. Frond strap-shaped, 

 gradually acuminate at the apex ; segments strapshaped or oblong- 

 strapsha} ted, obtuse or abruptly acute, rarely attenuated from near the 

 middle to the apex, very finely crenate-serrulate. Secondary veins 

 usually with 1 lateral vein below the terminal fork, or more rarely 

 only forked. 



Tar. ft. serratum. Willd. 



Stipes containing 2 vascular bundles. Frond oblong-strapshaped, 

 often abruptly acuminated at the apex ; segments strapshaped or 

 lanceolate-strapshaped, gradually acuminated, more or less distinctly 

 serrate or crenate, serrate at the margins. Secondary veins usually 

 with two lateral veins below the terminal fork. 



Yar. y. Cambricum. Willd. 

 P. Cambricum, Linn. Spec. Plant, p. 1546. 



Stipes containing two vascular bundles. Fronds lanceolate- or 

 ovate-oblong, abruptly acuminated ; segments lanceolate or elliptical, 

 irregularly pinnatifid, or some of them pinnatifid and on the same 

 frond, others serrate or crenate-serrate, or rarely all crenate, often 

 barren. Secondary veins with 2 or 3 lateral veins below the terminal 

 fork, or elongated so as to form midribs to the secondary segments, 

 in which case they give off simple or once-forked veins. 



On rocks, walls, steep banks, stumps of trees. Common, and gene- 

 rally distributed in England, Scotland, and Ireland. 



Var. /3 is much more rare, at least in Scotland. I have it from 



