Il8 OUR NATIVE FERNS AND THEIR ALLIES 



tate. South bank of Miami River, Florida. IMarcli, 1S87 

 {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. Kvaris, a bladder, and Ttre/ji'?, a fern, alluding to the in- 

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

 pheres ; contains five species. 



* Fronds ovate-lanceolate, bt — tripinnate. 



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

 ceolate, elongate, i°— 2° long, bi— tripinnatifid. pinnae lanceo- 

 late-oblong; I innules crowded, toothed or pinnatifid; rachis 

 wingless, often bearing bulblets underneath; indusia short, 

 truncate on tlie free side. {Aspidium btilbiferum Swz., Ne- 

 phrodium btilbiferum Michx.) New England to Virginia and 

 North Carolina. 



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

 long, i' — 2\' broad, bi — tripinnate; pinna: 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. dentata Hook. Like many 

 other so-called varieties it passes insensibly into the tvpical 

 form. {Aspidiuni 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' lorn:, 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 niimenMis. 

 Colorado {Brandcgec), north shore of Lake Superior, Labrador 

 {Butler), Mt. Albert, Gaspe, Quebec, and nortliward to Alaska. 



