In some states, like California, there are laws governing the information that
must be included on plant labels. Unfortunately, this only applies to outdoor
plants. Therefore, nursery stock which originates in California, like anything
from Monrovia, will be properly labeled.
The local nurseries are not going to do anything they are not forced to do by
law. And the mom-and-pop nurseries can't afford the time to research the
subject.
If you want named cultivars of a particular plant, you probably have to
patronize the specialist mail-order houses & pay the extra cost.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)