PROCKEDINGS 



OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol. VII, pp. 325-396. March 29, 1906. 



THE FOLIACEOUS AND FRUTICOSE LICHENS OF 

 THE SANTA CRUZ PENINSULA, CALIFORNIA. 



By Albert W. C. T. Herre, A.M. 



The following paper embodies some of the results of a study 

 of the lichens of the Santa Cruz peninsula, carried on during 

 the past three years. Only the foliaceous and fruticose lichens 

 are treated at present, the crustaceous lichens being reserved for 

 a later and more comprehensive paper. 



As a matter of fact a scientific treatment should take no 

 cognizance of the old arbitrary divisions into fruticose, folia- 

 ceous and crustaceous lichens, as they possess no significance 

 and members of one grouping merge gradually into another, 

 all forms being found in one family or even in one genus. In 

 a later paper the author hopes to present the chemical reac- 

 tions, spore measurements, and synonymy of all the lichens of 

 the Santa Cruz peninsula. The forms selected for treatment 

 in the present paper are mainly those which attract the attention 

 of the general botanist or amateur. 



The descriptions and keys have been written from a first-hand 

 study of material collected within the territory described below, 

 and accordingly may not apply in some cases to specimens of 

 the same species from other localities, or agree with Tucker- 

 man's descriptions. 



So far as possible, technicalities have been avoided and sim- 

 plicity, rather than brevity, has been the aim. In constructing 

 the keys an effort has been made to utilize those characters most 

 prominent in the field ; a more correct way would be to use the 

 natural characters and classification, rather than the artificial 

 plan followed. The author believes that it is possible to make 



Proc. Wash. Acad. Sci., March, 1906. (325) 



