THE LICHEN— FLORA OF LA SALLE 

 COUNTY. 



BY WILLIAM W. CALKINS AND JOHN W. HUETT. 



The following- list containing- thii'ty g-enera and 

 135 species and varieties indicates the richness of 

 our county in that humble class of plants known lis 

 Lichens, yet the authors do not claim to have exhausted 

 the field of research. La Salle county with its larg-e 

 area, diversity of soil and g-eolog-ical strata, as well as 

 extensive natural forests, offers inducements and situa- 

 tions peculiarly favorable to the g-rowth of the lower 

 orders of plant life, hence explorers who may follow 

 us will find many other species additional to those here 

 enumerated. 



Briefly defined, lichens are a natural order of 

 plants, having- neither stem, leaf, root or flower in the 

 usual acceptation of the term, deriving- their suste- 

 nance from the air, and stimulated or retarded in 

 g-rowth by the conditions of lig'ht, heat and moisture; 

 also intermediate between Alg-a^ and Fung-i, according- 

 to some learned scholars. But in the lig-ht of present 

 knowledg-e we must consider them as autonomous, not 

 being- in haste to concur in the opposite conclusions of 

 some authorities, however eminent. Neither shall w^e 

 forg-et that as reg-ards certain g-enera and species 

 (ANGIOCAPAI), we approach the border land of 

 FUNGI— as, for instance, SP.^RIA ! While enquiry 



