Tets just aren't easy to work with. I also have a hard time getting seed and when I do the flowers are poor, usually with petals that cup or abruptly fold downward.
Seems like going through the checklist and adding any that you know were introduced after the last publication should do it. Several years ago Dee made up a list for me from the 2006 checklist and that came to 26 so obviously more have been added since.
