Il8 OUR NATIVE FERNS AND THE IK ALLIES 



tate. South bank of Miami River, Florida. March, 1887 

 (H olden). 



XXII. CYSTOPTERIS Bernh. BLADDER-FERN. 



Sori roundish, borne on the back of the veins. Indusium 

 delicate, hood-like, or arched, attached by a broad base on the 

 inner side partly under the sorus, early opening, free at the other 

 side, and thrown back or withering away. Veins free. Name 

 from Gr. KVOTIS, a bladder, and itrepti, a fern, alluding to the in- 

 flated indusia. Found in the temperate zones of both hemis- 

 pheres; contains five species. 



* Fronds ovate-lanceolate, bi tripinnate. 



1. C. bulbifera (L.) Bernh. Stipes 4' 6' long ; fronds lan- 

 ceolate, elongate, i 2 long, bi tripinnatifid, pinnae lanceo- 

 late-oblong; pinnules crowded, toothed or pinnatifid ; rachis 

 wingless, often bearing bulblets underneath ; indusia short, 

 truncate on the free side. (Aspidium bulbiferum Swz., Ne- 

 phr odium bulbiferum Michx.) New England to Virginia and 

 North Carolina. 



2. C. fragilis (L.) Bernh. Fronds oblong-lanceolate, 4' 8' 

 long, i' 2^' broad, bi tripinnate ; pinnae and pinnules lanceo- 

 late or ovate in outline, decurrent along the margined or winged 

 rachis ; indusia tapering or acute at the free end. Narrower, 

 less divided specimens, barely bipinnate with obtuse and bluntly 

 toothed pinnules form the var. dent at a Hook. Like many 

 other so-called varieties it passes insensibly into the typical 

 form. (Aspidium tenue Swz.) New England to Arizona, Cali- 

 fornia, and northward. 



** Fronds deltoid-ovate, tri quadripinnate. 



3. C. montana (Lam.) Bernh. Rootstock slender, creeping ; 

 stipes 6' 9' long, slender; fronds about 6' each way; lowest 

 pinnae deltoid-lanceolate, much larger than those above, their 

 inferior pinnules i' i^' long; segments cut to the rachis into 

 oblong lobes, deeply and sharply toothed; sori numerous. 

 Colorado (Brandegee), north shore 'of Lake Superior, Labrador 

 Cutler), Mt. Albert, Gaspe, Quebec, and northward to Alaska. 



