NOTES ON THE PHYLOGENY OF LIRIODENDRON 



Edward W. Berry. 



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(with one figure) 



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There are many reasons why the tulip tree is an object of 



unusual interest, but its scientific interest chiefly arises from the 



facts that, like the Sequoia, Sassafras, Platanus, Ginkgo, etc., it is 



the lone survivor of an ancient race extending back into the 



Cretaceous period, that most of the race history can be traced, 



and that we find this history epitomized in the existing species. 



Liriodendron Tulipifera is confined to the eastern portions of 



North America and Asia, although it or its probably identical 



representatives were common in Europe during the Tertiary 



period. Like other trees peculiar to North America at the 



present time, such as Magnolia, Liquidambar, Sassafras, etc., 



and which inhabited Europe during the Tertiary, it was forced 



to the Mediterranean by the glaciers and exterminated. The 



existing Asiatic form has been described as a variety {chinensis^ ) ^ 



but it is very doubtful whether it is distinct. In North America 



the tulip tree is found from Vermont to Florida and westward to 



Michigan and Arkansas, and appears to be confined to the humid 



temperate realm, requiring a rich soil for its full development. 



The great variability among the leaves of the tulip tree, as 

 well as the resemblance of some of them to fossil species, has 

 attracted very little attention, possibly, as Holm suggests,' 

 because this variability is so well known as not to merit discus- 

 sion. The belief that this is not the case has led to the follow- 

 ing notes, extending over a number of years, and based upon 

 innumerable specimens. While these notes are incomplete and 



* Descriptions of some new phanerogams collected by Dr. Shearer in China, etc.. 

 Jour. Bot. 13 : 225. 1875. 



Enumeration of all plants known from China, etc. F. B. Forbes and W- ^' 

 Hemsley. Jour. Linn. Soc, 23:25. 1886. 



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^ Proc. U. S. Nat. Mus. 13 : 15-35. 1890; Box. Gaz. 20 : 312. 1895. 



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[JULY 



