Name: Evan Pioneer Valley south, MA, USA (Zone 6a)
I found a reference on The Plant List to what looks like a new(?) taxon database. I only tried a few species but got more misses than hits. Will this help clarify or confuse?
It looks like iPlants (2004-06) was the impetus for The Plant List (2010-). It was a pilot project covering just 8 families, of which 5 included only Madagascar endemics. Probably best to just ignore it except for the history of how The Plant List began.
There does seem to be a plethora of taxonomic databases, some of which disagree with each other. One more might have sunk the plant boat, so Phew indeed.