286 



BORDER SPECIES. 



At maturity the pinnules partly unroll and become more 

 or less flattened. Specimens intergrading between fer- 

 tile and sterile fronds are sometimes found. 



There are ' but two species of Crypto- 

 gramma in the world. The second species 

 inhabits the northern and elevated portions 

 of the Eastern Hemisphere. The two are very 

 much alike and our species was formerly con- 

 sidered a variety of the other. A few botanists 

 now incline to add the slender cliff brake to 

 this genus, which shows among other 

 things, that the lines dividing certain 

 genera are very slight indeed. The 

 generic name is in allusion to the way 

 in which the plant fruits. From the 

 appearance of the sterile fronds it is 

 frequently called the parsley fern. 



Notholana dealbata. 



Our single representative of the genus 

 Notholana extends no further east than 

 Missouri and Kansas where it grows in 

 the clefts of calcareous rocks. South- 

 ward it extends to Texas and Arizona. 

 Beyond its range, westward, there are up- 

 wards of a dozen species and of the thirty 

 or more that compose the genus, a large 

 majority are American. In the south- 

 western part of its range our plant meets 



ROCK BRAKE. ., . Ar r , . , .. 



Cryptogramma another species, N. mvea, of which it was 



acrostichoides. , , , . 



once considered to be a variety. 

 The fronds seldom reach a length of six inches and 



