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THE BOOK OF CHOICE FERNS. 



Ferns grow, and the variety in shape, size, texture, and cutting of 

 their fronds is very great. In some cases these are simple (undivided), 

 pinnate (once divided to the midrib), bi- or tripinnate (twice or three 

 times divided to the midrib), and as regards size they vary quite as 

 much, for this genus, which is composed mostly of evergreen species, 

 nearly all of easy culture, is represented in all parts of the globe by 

 numerous subjects varying from a few inches in height, as in A. alternans 

 and our well-known British A. Ruta-muraria and A. Trichomanes, to several 

 feet in length, like A. dimorphum and A. longissimum. The genus is very 

 rich in highly -ornamental plants suitable for decoration, and while some are 

 very distinct and really interesting from a botanical as well as from a com- 

 mercial point of view, the majority of them make grand specimens for 

 exhibition, and those with long, drooping fronds are, on account of their 

 leathery texture, particularly well adapted for growing in hanging baskets. 



The numerous Ferns forming the genus Asplenium have been split into 

 many divisions by various authorities, but those retained at present are the 

 following : 



Anisogonium (An-is-og-o'-ni-um), PresI, and Callipteeis (Cal-lip'-ter-is), 

 Bory. A r eins anastomosing (running into one another), the sori and their 

 involucres extending to both sides of some of them. 



Athyeium (Ath-yr'-i-uni), Roth. In this section, which contains all the 

 species of deciduous (not evergreen) habit comprised in the genus, the veins 

 are free, and the sori and their coverings are more or less curved, and 

 sometimes even horseshoe- shaped. 



Ceteeach (Ce'-ter-ach), Willdenow, and Hemldictyum (He-mid-ic'-ty-um), 

 Presl. The plants belonging to this small section have their veins anas- 

 tomosing towards the margin, and the sori single. 



CiENOETEEis (Casn-op'-ter-is), Bory, and Daeea (Da'-re-a), Jussieu. A 

 section composed of plants with either small, lanceolate (spear-shaped), or 

 ample and finely -divided fronds. In either case the veins are simple and 

 the ultimate divisions of the fronds narrowly linear ; the sori, also linear 

 or linear-oblong, are marginal or submarginal (situated upon, or close to, 

 the edge of the fertile pinnules). 



Diplazium (Dip-laz'-i-um), Swartz. In this section, which is extensive, 

 some plants have their fronds simple and entire (undivided), or nearly so ; 



