Il8 OUR NATIVE FERNS AND THEIR 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. KVGTIS, a bladder, and -jtrepis, 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. 



i. c. bulbifera 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, trun- 

 cate on the free side. (Aspidiwn bulbiferum Swz., Nephrodium 

 bulbiferum Michx.) New England to Virginia and North 

 Carolina. 



30/yy 2. C.fragills Bernh. Fronds oblong-lanceolate, 4' 8' long, 

 i 1 2f broad, bi tripinnate; pinnae and pinnules lanceolate or 

 ovate in outline, decurrent along the margined or winged 

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

 less divided sped me ns, barely bipinnate with obtuse and bluntly 

 toothed pinnules form the i>ar. dcntata 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 qtiadripinnate. 



3. C. montana Bernh. Rootstalk long, 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 

 {Butler}, Mt. Albert, Gaspe, Quebec, and northward to Alaska. 



