114 



THE BOOK OF CHOICE FERNS. 



leathery texture, are ample, either sub-orbicular or reniform (kidney-shaped), 

 and attached by a broad base ; their summit and their sides are free. All 

 the species contained in this section are natives of the Malayan Islands. 



Leucostegia (Leu-cos-teg'-i-a), /. Smith. The fronds of the plants 

 contained in this section vary in size and in texture ; with one exception 

 [L. ferulacea), in which they are finely and repeatedly divided, they are three 

 or four times divided half-way to the midrib, or pinnate (once divided to the 

 midrib). Their pinnules are uniform on the lower and upper side ; and the 

 involucres covering the sori are attached as in Humata, but smaller, narrower, 

 and thinner. Leucostegias are mostly inhabitants of Polynesia and Tropical 

 Asia, several extending to the Himalayas, some to New Zealand, but none to 

 either Africa or America. This section forms part of Moore's Acrophorus. 



LoxoscAPHE (Lox-os'-caph-e), Moore. This is a very natural group, 

 allied in habit to Darea^ but quite difierent in the fructification. All the 

 species of which it is composed have decompound (much-divided) fronds with 

 ultimate segments linear, and the involucres, which form a compressed sub- 

 orbicular or cup- shaped pouch at the side of the segments, are open at their 

 summit only. 



MiCROLEPiA (Mi-crol-ep'-i-a), /. Smith. A group of Ferns with fronds 

 very variable in size, texture, and cutting. Although a few species belonging 

 to it are American, this sub-genus has its head-quarters in South-Eastern 

 Asia and Polynesia. The involucres covering their sori are membranous (thin 

 and more or less transparent), shallowly half- cup -shaped, and attached at the 

 sides as well as at the base. Microlepias further differ from Eudavallias, 

 Humatas, and Leucostegias, in ha^dng the stems, except in D. ciliata, 

 continuous with the caudex (main trunk of the root), and consequently fall 

 under the primary division Desmobrya of J. Smith's classification, 



Odontoloma (Od-on-tol-o'-ma), Hooker. This is a small natural group, 

 very near the dimidiate Lindsayce, which it thus connects with Davallieoe. 

 They are nearly all inhabitants of Polynesia and South-Eastern Asia, and are 

 readily distinguished from all others through the shape and texture of their 

 pinnules, which are pellucido-herbaceous (thin, papery, and partly trans j)arent), 

 and dimidiate (resembling a quarter of a circle) in shape. Their involucres 

 (coverings of the spore masses) are similar to those of Leucostegia^ but have 

 a tendency to become confluent. 



