ECONOMIC USES OF LICHENS 



By George A. Llano 



Associate Curator, Division of Cryptogams 

 Department of Botany, United States National Museum 



[With 8 plates] 

 INTRODUCTION 



This article is a general discussion of most of the economic uses of 

 lichens. A more detailed account, including the biology of lichens, 

 was published by the present author (13)- in 1944, of which this 

 treatment is a revision of the economic uses only. Neither of these 

 papers is complete but merely an attempt to bring together some of 

 the information regarding utilization of lichens, and a working bib- 

 liography for those who have little familiarity with lichenology. None 

 of this material is available in text form ; most general texts mention 

 lichens in the most perfunctory manner, citing references only from 

 older texts which give little credit to modei-n studies. 



Though other branches of the botanical sciences have received con- 

 siderable impetus from the activities of research in recent years, little 

 of this force has carried over into the science of lichenology, which 

 is not a popular study. It is reserved to a few specialists throughout 

 the world whose studies are largely in the realm of lichen taxonomy, 

 geography, and ecology. To the few who have investigated the chem- 

 ical and physical as well as physiological structure of lichens, all li- 

 chenologists owe much for the stimulation they have given to the 

 science. Among these recent contributions attention should be di- 

 rected especially to that of Quispel (14) . 



BIOLOGY OF LICHENS 



Lichens can be distinguished by their habit of growth as crustose, 

 f ruticose, or f oliose. The first form is the simplest, growing on bark, 

 wood, rocks, or soil; the other two forms are more intricate, either 

 erect and branched or flat and leaflike, generally with a dorsal and 

 ventral surface, although some forms are pendent and cylindrical. 



1 Reprinted by permission from Economic Botany, vol. 2, No. 1, January-March 1948, with revisions by 

 the author. Dr. Llano is now research and editorial specialist, Arctic, Desert, Tropic Information Center, 

 Library Division, Headquarters Air University, United States Air Force, Maxwell Air Force Base 

 Alabama. 



' Numbers In parentheses refer to literature cited, at end of article. 



385 



