FERN FAMILY 99 



Mountain Spleenwort is a real cliff fern, pre- 

 ferring moist, shaded crevices and niches on 

 rocks in perilous situations. It is found only 

 rarely in southern New England. 



Most of the fronds are fertile. The fruit-dots 

 are linear, short, and few, and at length become 

 confluent, concealing the thin and narrow in- 

 dusia at maturity in July. 



WALL RUB SPLEENWORT. 



Asplcnium Ruta-viuraria. 



Frond twice or thrice pinnate at the base, 

 simply pinnate above, the pinnae long-stalked, 

 alternate ; the divisions few, small, distant, 

 stalked, wedged-shaped at the base, obtuse and 

 sharply toothed at the apex. 



The fronds are triangular-ovate in form, some- 

 what leathery in texture, and are evergreen. 

 The veins are forking. 



This fern bears some resemblance to Moun- 

 tain Spleenwort, but may be distinguished by 

 its triangular form, and by the peculiar wedge- 

 shaped form of its stalked divisions. 



Wall Rue Spleenwort is found in dry, rocky 

 situations, preferring limestone cliffs. It grows 

 in clusters, with long, flat, and smooth stipes, — 

 the entire length of the fern being from two to 

 six inches. It is not exactly rare, but occurs 

 only occasionally. 



