PaphMadMan
phytomanic
I still haven't seen any convincing pictures of a Paphmipedium, they have all looked like 100% Paphiopedilum crosses to me. We have been successful with Mexipedium x Phragmipedium crosses and got them to germinate in the lab, but like Eteson mentioned earlier, they were all poor growers in the lab (often kept proliferating, and never got any good looking seedlings). Only one cross ever made it out of the lab (wallisii x Mexipedium) but it never bloomed for us, and eventually died in the greenhouse.
Has anyone tried Cypripedium x Phragmipedium or Cypripedium x Paphiopedilum, I would think especially the more tropical Cypripediums (from Mexico or Southern China) might be able to produce compatible offspring when mated with Phrag's or Paph's...
Robert
When you had crosses with proliferation, did you ever try hormonal manipulation to trigger differentiation? That seems like it could be a relatively straight forward problem (for someone whose tissue culture experience is a lot more recent than mine).
If I wanted to place a bet, Cypripedium x Selenipedium would be the slipper intergeneric I'd put my money on.