AMERICAN SPECIES OF ALECTORIA OC- 

 CURRING NORTH OF THE FIFTEENTH 

 PARALLEL 



R. Heber Howe, Jr. 

 (With Plates 41-47, Containing 32 Figures) 



While I have been pursuing an intensive study of Usnea and 

 Evemia, the results of which have appeared in the Bulletin of 

 the Torrey Botanical Club and the Botanical Gazette, I have also 

 been collecting data for this review of Alectoria. The present 

 paper therefore represents the work of over six years, which dur- 

 ing the past winter I have brought into form for publication. 



The genus Alectoria was proposed by Acharius in 1810, and 

 was later limited by Nylander. Though Acharius included under 

 his Alectoria several species now removed to other allied genera, 

 his species cannot be considered " altogether incoherent," and 

 the genus must be credited to him. Almost since its proposal, 

 the question of spore-colors has led lichenologists to divide it 

 into two taxonomic units. The argument of Tuckerman (Gen. 

 Lich. 14-16. 1872) still holds undeniably true; while I also quite 

 agree with Th. Fries (Lich. Scand. 19-28. 1871), and later Dr. 

 Zahlbruckner, in the recognition of a sectional separation to dis- 

 tinguish species of Alectoria which are distinct in the number and 

 color of their spores. Such a distinction is, however, better 

 worthy of sectional than generic separation, and is adopted only 

 to elucidate the problem of classification that presents itself. 

 Stizenberger in a most valuable paper on the genus (Die Alec- 

 torienarten und ihre geographische Verbreitung, Annal. K. K. 

 Nat. Hofmuseums, 7: 1 17-134. 1892) also recognized subgenera. 



The following genera have included at various times species 

 still considered in the genus Alectoria, though few of these names 

 can be classed as true generic synonyms: Lichen L. 1753; Usnea 

 Web. 1780; Lobaria Hoffm. 1795; Parmelia Ach. 1803; Cornicu- 

 laria Ach. 1803; Setaria Ach. 1798, Mich. 1803; Evemia Fr. 



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