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SPECIFIC LIMITS IN ASTER 
Aster as now recognized forms a very large genus of over 300 
species. It possesses remarkable solidarity and coherence within 
the United States. Here the center of its distribution lies, cover- 
ing especially the eastern half of the continent, where perhaps two 
thirds of the known species of the genus are located. Northward 
its species extend through Canada into Labrador and Alaska; 
southward a few occur through Mexico and onward into the 
Chilean Andes. Southern reputed representatives in the Old 
World have not been able to retain their original position within the 
genus Aster. Those of the Cape of Good Hope, of Australia and 
of Tasmania, have been erected into small corollary genera. The 
Old World Asters as now understood are thus confined to Europe 
and Asia. Early species which had been described from China, 
Madagascar and Oahu, were separated by Nees in 1832. Nees 
still retained (besides the 5 North American Asters then placed 
in his Euryóia) 102 species in Aster proper, a number now nearly 
trebled. Of his 102, all but 20 were in the United States and 
Canada; 6 others were from mountains of tropical America, in 
Mexico and in the Andes from Colombia to Chile; the remain- 
der included 1 from Japan, 1 from Siberia, 8 from Nepal, 2 from 
the Cape of Good Hope, 2 from New Zealand. Many others 
have since been added to the representation in Asia, including an 
endemic species in Formosa, others in the Kuriles and on the 
Amoor in Manchuria, several in Siberia, and others still in the Him- 
alayan region. 
The center of gravity of the genus however still remains in the 
eastern half of the United States, where Aster seems not only to 
exhibit its greatest number of species but also its greatest pro- 
fusion of individuals, its greatest variability, its greatest size and 
greatest beauty, and where, if the combination of these evidences 
can show it, the genus is presumably not geologically an immigrant 
but a native. 
Memoirs Torrey Botanical Club, Volume 13. 
