Sol,
Basically right although your tectorums with 10" flowers are something I want to see! 10" STALKS maybe although some are bigger especially the larger forms.
Both 'Persephone' and 'Lion King' have huge stalks, although cantabricums aren't as big as 'Lion King' but the shape is similar and the blooms look almost identical. Howard Wills thought the same although he told me that 'Lion King' just appeared so he doesn't know the pedigree. Calcareum has very small branches so it makes for a very tight cluster.
My 12" in diameter semp seedlings have enormous stalks, with over 200 flowers on the stalk. You can't believe how much seed that have generated. I'll be plowing a field in the spring to have space to row them out.
My arachnoideum 'Album' that I had as a kid came from Peter Mitchell and I'm betting its the same clone that Howard Wills has too.
My grandiflorum F2's have an odd mauve color to their flowers that definitely show both the marmoreum and grandiflorum colors overlaid. You get the same sort of blends of anthocyanins and carotenoids in irises. Oddly enough, I've never seen a pure yellow flower segregate back out of wulfenii hybrids like 'Silverine' although I do get some quite pale ones. I'm sure the presence and distribution of pigments is controlled by a large number of genes and of course I'm selecting for rosettes not flowers so I may have missed/ pitched the pale or yellow ones. I saved 4 very wulfenii-looking seedlings from 'Silver Song' X self so it will be interesting to see if I get yellow flowers back too.
Kevin