, Robert ! As was stated, lots of good pictures are almost a must.......also notes on height.....measure from the top of the bloom, to the ground, foliage color......dark green ? Light green ? 'Stained" purple at the bottom (that's 'PBF"="purple based foliage") ? "Season of bloom" (is it the first iris in your garden to bloom ? or the last ?Does it ever bloom again in late summer or fall ?) How long have you had it ? (or, how long have you "known it to be grown" ? i.e. ,if you got it from your sister , who first had it in 1990.....that eliminates anything that came on the market SINCE 1990.
My first stop , when trying for an ID, is cruising a few vendors sites, and checking some of their photos, same for the searchable data base , here. Those are also good resources to learn what a "self" is, what a "plicata" is, so you can describe, in words, what you have. Then, you can say, I have an iris, 34"-36" tall, seems to bloom mid season, has dark green leaves, with no pbf. it's a yellow self, with a yellow beard, and it has to be older than 1998.
Identifying an iris can be an enjoyable....but sometimes very exasperating......trip to take ! But, even if you never "nail down" an ID, you'll learn a lot, and make quite a few "iris buddies" along the way !