Asteraceae and connections

[Richard L. Brown]

I am interested in knowing more about geographic origin of Asteraceae and
connections between the Great Plains and eastern U.S., e.g., Piedmont and
Coastal Plain.  I have assumed that Asteraceae diversified in Great Plains,
but I recall a paper several years ago that suggested that the group
originated in eastern U.S.  Can anyone advise me about the citation of the
latter paper or other references regarding biogeographic relationships of
Asteraceae.

There are distributional data of moths to support an extension of
grasslands from the Great Plains into New York and the eastern coast via an
area north of Lake Erie and south of Lake Ontario (either that or a
concentration of collectors picking up vagrant species in the area).  Does
anyone know of references to support a connecting grasslands between the
upper midwest and upper Atlantic coast?  Thanks,

Richard L. Brown
Mississippi Entomological Museum
Box 9775
Mississippi State, MS 39762
phone: (662) 325-2085
fax: (662) 325-8837
e-mail: moth at ra.msstate.edu