Filices Adiantum. 545 



A. pedatum, a species occurring both in North America and 

 Asia, is nearly or quite hardy in suitable situations. It has 

 dichotomous fronds, the main divisions of which are flabellately 

 branched, and small dimidiate pinnules broadest on the side 

 nearest the stem. 



2. PTERIS. 



Rhizome creeping. Frond coriaceous, 3- or 4-pinnate ; veins 

 free. Sori marginal, continuous. Indusium membranous, con- 

 fluent with the recurved margin. A large genus containing about 

 eighty species, found in all parts of the world except the very 

 coldest. The name is from Trrspoit, a wing, in allusion to the 

 form of the fronds. 



1. P. aquilina. Brake or Bracken. It is unnecessary to 

 describe this the commonest of all native Ferns in detail. In 

 different situations its fronds vary from 1 to 8 feet or more 

 high, with a tall stout stipes. This Fern is found in nearly all 

 parts of the world. 



3. CRYPTOGRAMME. 



Rhizome tufted. Fronds 2- to 4-pinnatifid, outer sterile, 

 inner fertile ; veins forked, free. Sori terminal, nearly circular, 

 at length continuous. Indusium continuous with the reflexed 

 margin of the pinnules. This genus is limited to the following 

 species, which is widely dispersed throughout the north tempe- 

 rate and arctic regions. The name is compounded of Kpvjnos^ 

 hidden, and ypa/ji/jirj, writing, in allusion to the concealed sori. 



1. C. crispa, syn. Allosorus crispus. Parsley Fern, Rock 

 Brake. A dwarf tufted Fern with Parsley-like barren fronds, 

 about 8 inches high, tri pinnate ; pinnules bi-tri-pinnatifid ; 

 stipes short. This plant is found in mountainous districts in 

 Britain, and extends to Asia and North America. 



4. LOMARIA. 



Rhizome tufted or creeping. Fronds once pinnate or pinna- 

 tifid ; outer spreading, barren ; inner erect, slender, and fertile. 

 Sori linear, covering the under side of the pinnules. Indusium 

 scarious. There are forty species referred to the genus. The 

 name is from Vo//a, a border, or fringe, the marginal sori. 



1. L. Spicant, syn. Blechnum boreale. Hard Fern. Fronds 

 tufted, 12 to 18 inches high ; barren ones lanceolate in outline, 

 pinnate below, pinnatifid upwards ; pinnules oblong. There are 



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