For the curious, here's a quick summary of what I was able to find
about Iris pseudacorus as a noxious weed.
Some states and provinces treat it like a non-ornamental weed where
you must by law eradicate it on land you own: California, Montana,
Washington, Alberta, British Columbia.
Others treat it like an invasive ornamental where it is illegal to
sell or propagate it: Connecticut, Massachusetts, New Hampshire,
Oregon, Vermont. In Connecticut it is specifically illegal to
cultivate and existing plants must be destroyed. Vermont's ban doesn't
take effect until July 1, 2013.
In Minnesota it is legal to buy and sell, but is a "regulated
invasive" that is illegal to release into the wild.
These laws should probably be assumed to include all cultivars,
varieties and hybrids, and to ban trades and gifts as well as outright
sale. Massachusetts clearly prohibits all of the above, while
Connecticut allows hybrids unless specifically banned.
Few other irids are currently considered noxious weeds. The US bans
Moraea collina, M. flaccida, M. miniata, M. ochroleuca and M. pallida
(all formerly Homeria spp.) without a permit. California prohibits
Watsonia meriana v. bulbillifera.
Sean Z
Zone 6a
SE Michigan
