1040 



THE FERN FAMILY. 



In rather dry woods, in "Europe and 

 Russian Asia, from the Mediterranean to 

 the Arctic regions, and in North Ame- 

 rica. Not uncommon in western, cen- 

 tral, and northern England and Scot- 

 land, and occurs also in Ireland. Fr. 

 summer and autumn. The limestone 

 Polypody (P. ealcareum, Eng. Bot. t. 

 1525, P. Robertianum, Bab. Man.) ap- 

 pears to be a mere variety of the Oak 

 P., of rather stouter growth, usually 

 with rather less difference in size between 

 the lower pair of pinnules and the suc- 

 ceeding ones, and has a minute, scaly 

 or glandular meal on the frond-stalk 

 and principal veins. It occurs here and 

 there, in more open rocky situations than 

 the common form, and especially in lime- 

 stone districts. 



Y. ALLOSORUS. ALLOSOEUS. 



Delicate Ferns, with tufted, much divided fronds ; the central ones 

 erect and fruiting ; the outer ones barren, with broader segments! Sori 

 circular, but so close as to form compact lines along the margins, co- 

 vered over when young by the thin edge of the frond itself. 



A small genus, confined to the mountainous or northern districts of 

 the northern hemisphere. 



1. Curled Allosorus. Allosorus crispus, Bernh. (Fig. 1205.) 



(JPteris, Eng. Bot. t. 1160. Cryptogamma, Brit. Fl. Rock Brakes, 

 Parsley Fern.) 



Stock densely tufted with brown scarious scales. Fronds 2 or 3 times 

 pinnate, ovate or oblong in their general outline, on slender stalks al- 

 most without scarious scales ; the outer barren ones about 5 or 6 inches 

 high, somewhat resembling parsley-leaves, with numerous small, obovate 



