^93] ENGELMANH-^-A SVNOFSlS OF THE AMERICAN FIRS. 
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A Synopsis of the American Firs (Abies Link.)* 
By Dr. George Eisgelmann. 
Great confusion prevails in regard to the distinction of species * 
of our Firs and in their synonymy. This is owing partly to the 
innate difficulty of the subject and to the very imperfect descrip¬ 
tions in the books, and partly to the inordinate zeal of seed col¬ 
lectors and horticulturists. But in the last decade, the western 
mountain regions, the homes of most of our firs, have been more 
fully explored and the geographical limits of the species ascer¬ 
tained ; and in about the same period the anatomical structure of 
their leaves has been ‘investigated, and has furnished welcome aid 
irt the distinction and the classification of the species. 
It is almost interesting as well as significant fact that while 
the anatomical structure of the leaves of higher organized plants 
shows considerable uniformity, so that it rarely can be made 
available for diagnostic purposes, the conifers exhibit such a 
wonderful variety of leaf-structure (approaching thereby the low¬ 
est orders of vascular plants), that often a single leaf is sufficient 
to recognize the genus, and often the species, even when the ordi¬ 
nary characters may leave us in doubt. 
The anatomy of coniferous leaves has been often examined into, 
but the first to appreciate their characters as a means of classifi¬ 
cation was F. Thomas, who in 1865 published an extensive trea¬ 
tise on the subject in Pringsheim’s Jahrb. 4, pp. 23-63. He was 
followed in 1871 by C. E. Bertrand, Bull. Soc. Bot. France , 
18, pp. 376-81. The same author gave a more elaborate paper 
on this subject in 1874 in Ann. Set. Nat. Bo£. 20, pp. 5-153, with 
12 plates. He was followed in the succeeding year by W. R. Me 
Nab in Proc. Irish Acad. 2, pp. 209-13, with 1 plate; and in 
* I follow Link (Linncea, 15, 525, 1841) in his name, definition, and circumscription of 
synonym Picea Don, in Loudon Arb. 4, 2329, 1838, is the older name and enjoys t..e Lin- 
nean prestige, but is contrary to classical (Plinius, etc.) and philological authority. The 
name Abies is generally adopted on the continent of Europe, while Picea was heretofore 
principally used in England, but is now being abandoned. Picea Link (the same as Abies 
Don) is the proper name for the spruces. Tournefort, the elder DeCanddlle, Gray and 
others, comprise under the name of Abies both firs and spruces. The generic distinctions 
• . . UMfiUEN 
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