The Iris is a Difficult Flower to Cross-Pollenize
To casual inspection, the iris does not appear to be a perfect flower. That is to say, it seems to lack stamens and pistils of the ordinary type. In point of fact, the iris has organs of fertilization that are quite petal-like in appearance, arranged in such a manner as to provide against self-fertilization. But intelligent inspection will enable the would-be pollenizer to solve their mysteries without great difficulty.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 10 Chapter 2