When I was a kid we called these "Flags" but they are rightly called Iris. There are many varieties in all shades of red, yellow, blue and white. Iris grow from rhizomes which multiply and spread underground. Once established they require almost no care. They bloom every spring without fail. The only impediment to immortality is that they eventually get too crowded and need to be thinned out. As a result if you stop to admire the iris in an old lady's garden it would not be uncommon for her to dig up a clump and send it with you. And they smell like grapes.