160 GUIDE TO THE STUDY OF LICHENS. 



general system. The plant has, however, no active 

 curative property, and is fast going into disuse as a 

 medicine. 



8. Ramalina. 



In this genus the thallus is typically fruticose, the 

 lobes being flattened. In the majority of species the 

 surface is smooth. The length of the thallus varies 

 greatly ; in the smallest species an inch or less to 

 several feet in the largest. The branches are strap- 

 shaped, and in a few species tend to become cylin- 

 drical. Color varies from greenish to gray or even 

 brown. Large soralia occur on some species. 



The apothecia vary from rather small to medium in 

 size. They are flattened or cup-shaped, lateral, occur- 

 ring either along the margin or upon the flat surface. 

 Disk pale brown. Spores are colorless, elliptical, two- 

 celled. 



The Ramalinas occur upon trees and rocks ; they 

 are not plentiful. 



i. Ramalina minuscula. Thallus minute, half an 

 inch or less in height, branches canaliculate ; ter- 

 minal branches very short ; soralia sometimes present ; 

 color light-gray. Apothecia and spores not seen. 



2. RarnaUna calicaris. Thallus one or two inches 

 in height ; lobes comparatively thin and broad, some- 

 what canaliculate aud slightly reticulate, green. Apo- 

 thecia of medium size, terminal tendency, somewhat 

 cup-shaped. Disk light-brown. Spores typical, not 

 curved, 10.5/x, X 5.5/a. 



Most authors recognize a number of varieties, some 

 of which no doubt deserve the rank of species. R, 



