Iris is my choice for several reasons. First, the bearded iris, which we are beginning to see now here in Hometown, is one of my favorite flowers. There are so many striking varieties in an entire palette of colors. Yet even the lowly wild iris with yellow stands and brown falls is lovely to behold. The typical lavender flower with falls and stands of the same color may be the blossom that springs to mind for most people since it is quite common. In the yard of a previous residence we had 13 varieties of the bearded iris.
iris (n.) The iris is a thin disc in the eye which controls the size of the pupil opening and thus the amount of light that reaches the retina. The iris is that part of the eye that imparts eye-color so if the iris is brown we say, "She has brown eyes," and so on.
Such an important element of our sense of sight deserves to be recognized. My father literally made it a practice to note eye color and recognize people years later by that feature.
My wife says I have amazingly green eyes. My driver's license says they are hazel. (Some "experts" on the topic say that "hazel" and "green" are two distinctly different eye colors.) I am sure that we have all noted eyes of many colors: brown, blue, hazel, green, grey, gold, and so on. I think probably all eyes are either brown or blue in some variation, but what a variety! My wife's eyes are a deep brown, you know, those eyes I fell into right away! Yet she had a brother whose eyes were such a startlingly brilliant blue one could never forget them. (Yet with today's technology, tinted contacts and such, who knows what color anyone's eyes might be.)
The term iris may also be applied to a rainbow or a rainbow-like appearance in an object. Also Iris was a messenger of the gods in classical mythology.