This past Saturday, Longue Vue House and Garden held its “Iris Day” emphasizing the contributions of Caroline Dormon, the Louisiana conservationist who originally designed the Wild Garden there, I think in the 1940s. The event was very nice but was one of the casualties of the lingering winter since only a half dozen irises were in bloom. All were species, including several fulvas, a giganticaerulea and an I. hexagona collected by Benny Trahan in Florida.
All the irises were pretty, but the hexagona was the one that interested me most, for two reasons: one, in form the flower looked exactly like a Louisiana giganticaerulea, but the plant was notably shorter. Two, it was an early bloomer, right there with the fulva and giganticearulea, which are known to be early. And yet, one of the characteristics associated with I. hexagona is that it is a late bloomer. In fact, plants from South Carolina given to me as I. hexagona have always bloomed very late, just as does I. brevicaulis, reputed to be the latest blooming Louisiana.
So, what’s up? Just a fluke in an oddball bloom season? Anything is possible and you shouldn’t generalize from a single instance. But who’s going to stop me? I fall in with those who think that the taxonomy of the native irises of Florida has not been entirely sorted out yet. The generally accepted view is that all the native irises of Florida that are broadly in the Louisiana group are I. hexagona and that I. hexagona is limited to the East Coast of the U. S. (not including Louisiana). It would not surprise me if careful study eventually concluded that some irises in Florida were essentially the same thing as Louisiana’s giganticaeruleas, but that others are significantly different critters.
One difference between the Florida iris blooming at Longue Vue this week and Louisiana gigantaeruleas is that the Florida flower is a much deeper blue. I would call it a blue-purple. Giganticaeruleas are much lighter blue, sometimes light lavender, or even pale blue approaching white. By no means are all Florida irises this dark, but except for hybrids, irises found in Louisiana don’t show such a dark blue.
It is unfortunate that the Florida natives have barely worked their way into the ancestry of the modern Louisiana iris hybrids. The sensation caused by the discovery of Louisiana irises in the 1920s and 1930s was limited to Louisiana itself where the vast bulk of collecting occurred and where amazingly varied natural hybrids were found. With scant exception, the stock of the modern hybrids originated in Louisiana. But given that dark blue color found in Florida, that is an unfortunate omission.
Those interested in Florida’s native irises might want to check out an article that appeared in the Society for Louisiana Irises’ quarterly magazine.