Hi Tim,
I think Anecphya have been in a flux because there has been so little research on them until recently. I had the great pleasure this past summer of meeting and having a long conversation with Dr. Barre Hellequist who is involved in most of the present work on taxonomy in Anecphya. A lot of it involved the evolutionary divergence within a couple complexes, one being N. gigantea and the other I think was N. macrosperma. Things have gotten more sophisticated and now DNA markers are being used to chart the divergence more so than morphological differences. For me it was one of the more fascinating afteroons I've spent in recent memory. One offshoot of it was that I the new seed. A mix of species and their various forms from 19 collection sites with some of the relevant data on environmental conditions...and don't let anyone tell you that Anecphya can't take heat. Now I just need to get them to grow.<g> I'm especially taken with N. violacea and I now have seed for the white, pink and blue forms.
As for hybridizing.....I haven't used named cultivars ( at least other peoples') for some years now, so can't be much help in saying which hybrids are fertile and which sterile for podand/or pollen. Hybrids break down when they are crossed and the F2 generation can be a crap shoot. It isn't a linear process, so there really is no way of knowing what the progeny will look like..or even what color they will be. So I developed some of my own lines that seem to have 'fixed' the traits I find desireable...like the moptops. Sounds good...but mostly it has been pure luck.<g>
The downside is they are very weakly fertile and I get very few seed, but since I don't sell seed ( though I give seed away for the asking without reference to the parents as that is largely meaningless if not misleading), that is a non- factor because instead of getting gobs of seed producing a homogenous batch of so-so looking lilies, when I do get seed ( often fewer than 10 good seed per pod) the chances of getting something I like have been greater, but I go long stretches getting nothing.
Sorry to ramble, but it is a subject I like to run off at the mouth about.<g> The point in all of this is that it does take time to find which lilies produce fertile seed but a microscope will tell you almost immediately if you are working with viable pollen. If you get into hybridizing seriously, a microscope is well worth the investment.