

I Vol. 35 



BULLETIN 



No 8 



OF THE 



TORREY BOTANICAL CLUB 





AUGUST, 1908 





New West Indian Lejeuneae 



Alexander William Evans 

 (with plates 26-28) 



Students of the Hepaticae cannot help being impressed by the 



remarkable development of the Lejeuneae in tropical regions. 



Usually more than half of the species in any particular locality 



belong to this group, and many of the species are represented by 



numerous individuals. The Lejeuneae have become adapted to a 



great variety of external conditions. Some are true xerophytes 



and are able to endure desiccation for considerable periods ; others 



cannot exist except in the constant shade of moist forests. Some 



grow on rocks or on the bark of trees, others are found only on 



•ving leaves, while still others carry on their entire development 



within the tufts of larger bryophytes. In all probability the group 



is essentially modern, and the species have acquired their great 



iversity of form and their manifold adaptations to peculiar modes 



], k within comparatively recent times. 

 ^ he West Indies agree with other tropical regions in showing 



ar ge preponderance of Lejeuneae. In a series of papers on the 

 jpaticae of Puerto Rico * the writer has recently had occasion 



of v e h Cnbe and figure more than fifty s P ecies in the g rou P> man y 



limit ,Ch haVC a geo £ ra P hical ran g e extending far beyond the 



des' ' °^ thlS particular isl and. In connection with the specific 



^captions the genera to which the species are referred are also 



cussed, and in several instances it has seemed advisable to pro- 



ff iv k W genera or to em end the characters of accepted genera as 

 _ en y earlier writers. In the course of this study other West 



U.ETIN for July, 1908 ( 35 , 321-370.//. 21-25) ™s issued 30 Jl 1908.] 



371 



