Can anyone recommend sources, either Seattle-area stores or mail-order places? Thanks very much.

http://www.wildseedfarms.com/

http://www.americanmeadows.com/WildflowerSeeds.aspx

http://www.prairiemoon.com/

http://www.swallowtailgardenseeds.com/index.shtml

http://www.cheapseeds.com/

Also, here is a great link to a bunch of seed sites.

http://www.sunmarkseeds.com

they just redesigned their website and its horrible. they have a "pacific NW mix" of wildflowers for $25 a pound. i haven't followed all the links above, but that price beats clyde robins and american meadows by a third.