90 The Fern Lover's Cojipaxiox 



apex. Veins forking. Rachis and stipe green. Sori few, 

 soon confluent. 



This tiny fern grows from small fissures in the lime- 

 stone cliffs, and is rather rare in this country; but in 

 Great Britain it is A-ery common, growing everywhere on 

 walls and ruins. From Mt. Toby, Mass., and Wilioughby 

 INIountain, Vt., to Michigan, Missouri, Kentucky and 

 southward. 



E. The Large Spleenworts. Athyrium 



The following species, which are often two to three feet 

 high and grow in rich soil, are cjuite different in appearance 

 and habits from the small rock spleenworts just described. 

 Some botanists have kept them in the genus Aspleniiini 

 because their sori are usually rather straight or only 

 slightly curved, but others are inclined to follow the 

 practice of the Briti-sh botanists and put them into a 

 separate group under Athi/rium. Nearly all agree that 

 the lady fern, with its variously curved sori, should be 

 placed here, and many others would place the silvery 

 spleenwort in the same genus, partly Ijecause of its fre- 

 cjuently doubled sori. In regard to the last member of 

 the group, the narrow-leaved spleenwort, there is more 

 doubt. The sori taken separately would place it with the 

 Aspleniiims, liut considering its size, structure, habits of 

 growth and all, it seems more closely allied to the two 

 larger ferns than to the little rock species. We shall 

 grou]i the three together as the large sj)leenworts, or for 

 the sake of being more definite adopt ('lute's felicitous 

 phrase. 



