I'm quite besotted with Louisiana iris. Part of my fascination, of course, is that the deer leave all types of iris alone. But in addition to Bambi's disdain, these iris have other endearing attributes.
They are absolutely beautiful, either in the garden or in a vase, where they almost arrange themselves. They extend the iris-blooming season because they flower after most other iris have finished their show.
In the Midwest they bloom in June after the Japanese iris have finished, and in the south they bloom in April. They are native to the south, where they grow in swamps and wetlands, so they adore locations in our gardens that are moist, such as under downspouts and on the edge of ponds. They don't mind heat and humidity and are vigorous growers in fertile soil that is rich in organic matter.
Grow them in zones 4 to 9 and watch them spread when they are happy with their site.
I got my first one, ‘Black Gamecock', at a plant swap and was immediately smitten when it bloomed a flat bloom from 3 to 8 inches across, similar to a Siberian iris in some respects, and a velvety purple-black with small yellow markings. Louisiana iris come in the widest range of colors of any iris. I am now ordering every color that I can find!