TULIP-TREE 
sown in autumn they come up the succeeding spring, but if 
sown in spring they often remain a year in the ground, It 
is readily propagated by cuttings and easily transplanted. 
The Liriodendron is now a genus of a single species. In 
the cretaceous age the genus was represented by several spe- 
cies, and was widely distributed over North America and 
Europe. Its remains are also found in the tertiary rocks. 
One species alone survived the glacial ice, and this is found 
only in eastern North America and western China—the well- 
known Tulip-tree of the western states. 
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