The genus Usnea and its Linnaean nomenclature 
R. Heser Howe, Jr. 
When I published my paper on the North American Usneas 
(Bull. Torrey Club 37: 1-18. 1910) the International Botanical 
Congress had not accepted Linnaeus’ Species Plantarum of 1753 
as a starting point for lichenological nomenclature. This adoption 
having been settled upon in May of the present year, it seems well 
worth while to fix the disposition of Linnaean names in this genus, 
in fact as soon as possible in all genera. 
With the adoption of Species Plantarum is opened perhaps the 
necessity of referring to the Linnaean herbarium for type material, 
a matter needing a word of explanation. In 1886 Wainio (Meddel. 
Soc. Fauna et Flora Fenn. 14: 1-10) published an account of the 
material found in the Linnaean herbarium,* showing that a large 
number of the lichen species were either not represented at all 
(45 out of 80) or were compositely shown by several species. It 
seems quite clear that although Linnaeus referred almost always 
(13 exceptions) to the figures and descriptions of Dillenius, yet 
in Linnaeus’ own collection the species were poorly represented 
and authentic material rare. Crombie has given us a careful re- 
port on the Dillenian herbarium, in which he found a much greater 
percentage of species, properly represented and figured in the 
author’s Historia Muscorum, than Wainio did in Linnaeus’ col- 
lections and work. We must therefore not put too much weight 
on the supposed Linnaean “‘types,” of which Linnaeus himself 
makes no definite mention,t but must take Linnaeus’ original 
descriptions for what they are wore. and supplement theme with 
*To most : the specimens specific names had been ascribed by Linnaeus himself. 
same specimens, either alone or placed before the e names, which 
The numbers o: 
were likewise pote by Linnaeus himself, refer to his Species Plantarum (1753) 
and the numbers enclosed in parenthesis to Flora Sueccia. But to many speci- 
mens names were ascribed by authorities after Linnaeus’ time, such as Smith, 
eae. Swartz. [Translation of a part of Wainio's preface e.] nett 
‘It has happened that I have come into possession of no slight collection. 
[Translation from preface of Tomus I.] 
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