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It is called the iris. The part of a camera that serves the same purpose is also called an iris, or a diaphram.
http://en.wikipedia.org/wiki/Iris_(anatomy)
There are bearded iris, water iris, dwarf iris, Louisiana iris, and siberian iris. There is also blackberry iris.
Iris - Iris album - was created in 1984.
There are over 200 species of iris including Japanese iris, Siberian iris, German iris, Louisiana iris, and water iris.
Iris to Iris is a Christian rock CD by Building 429. It came our in 2007.