[ECOLOG-L] spring wildflowers visited by Ruby-throated Hummingbirds?

[David Inouye]

http://www.hummingbirds.net/map.html reports that Ruby-throated 
Hummingbirds have already arrived in Canada this month (3 weeks 
earlier than last year).  What wildflowers do they usually visit 
during their spring migration, and are they already in bloom?

David Inouye