You guys are WAY ahead of me, but here is something I noticed.
When I open the Lettuces Database and do a search using the search dialog in the middle of the page,
not the one in the far-left column, only the Lettuces Database is searched.
In this website, most of the search dialogs are context sensitive: they search only the subset of the website that corresponds to the location of the search dialog. I think the following is accurate.
The search dialog in the middle of the Lettuces Database front page searches only the the Lettuces Database. (That makes a cultivar-name-only search practical).
The search dialogs in the far-left column of Plant Database pages search the whole Plant Database.
The search dialog in the Tree-Mail area searches your Tree Mail.
The search dialog in the ATP Home Page searches the whole site.