THE ROCK SPLEENWORTS. 



nooks on dry cliffs and often grows luxuriantly 

 in the smallest crevices. In comparison with 

 many of its allies it may be called common and 

 next to A. Trichomanes is the spleenwort oftenest 

 found on cliffs. 



The fronds grow in tufts from a short rootstalk 

 and are seldom more than five inches long, while 

 fruiting specimens only an inch high are not rare. 

 In shape, they vary from ovate to oblong-ovate 

 and are twice pinnate with stalked pinnae and 

 pinnules. The pinnae are shaped like the 

 frond, and the pinnules are ovate, obovate 

 or fan shaped with the outer margin slightly 

 toothed. Occasionally the pinnules are 

 lobed or again pinnate. In texture the 

 fronds are thick and leathery and they en- 

 dure the winter without injury. Several sori 

 are borne on each pinnule and nearly every 

 frond is fertile. The indusium soon withers 

 and the sori become confluent over nearly all 

 the under surface. 



Small as this species is, it does not lack for 

 common names. Among them, wall rue and 

 stone fern are in allusion to its place of growth, 

 and white maidenhair from its being confused 

 with the maidenhair spleenwort. Its old name 

 of tent-wort was originally taint-wort and was 

 given because the plant was supposed to be a 

 specific for a scrofulous disease called " the taint." 

 The fronds were once considered good'for coughs 

 and for diseases of the liver and spleen, but their 

 use for such things has now been abandoned. 



The rue spleenwort is found from Vermont, 



THE WALL RUE. 

 Asplenium ruta-muraria. Three forms of fronds. 



