These are quite rare and I can't find much info on the single flower variety, as it's different than the double variety. I won them but ran out of growing space. I do know they require cold stratification to sprout.
Seeds are tiny, brown, with hairs, much like mini hibiscus syriacus seeds, but these plants die back in cold climates and come back late spring unlike syriacus that has branches all year, perhaps this has hybrid genetics?
Send a tree mail with your address if interested.