I have no problem believing in mixed ploidy matings giving offspring.
I have three such seedlings growing out front currently:
'Pink Champagne' X 'Astra Girl'
'Honky Tonk Blues' X 'Astra Girl'
[both of these bloomed this Spring, and both set some seeds]
'Introspection' X 'Easy Smile'
[hopefully will bloom in 2013]
And I have other seeds that I hope will germinate from similar kinds of matings.

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Even though most people do not believe 'Bessie Bell' is a mixed ploidy iris (meaning that a bee got there before me...) i am glad you have noticed the different kind of things it gives!

For the moment i have registered only 'Ding Dong Bell', the 3 others are still garden names, i am holding them another year to be sure. But i am amazed at the quality it gave paired with 'Clown Pants' !
Surely some of the genes from 'High Master' are still there!