Hi Thomas,
That is exactly the problem I am struggling with. The manmade hybrids are registered and any cultivar derived from it is registered as well and can only be propagated vegatively but that all depends on documenting the origin of the plant one grows. It seems in Pleione that is were it goes wrong as very few collectors seem to know the origin of their plants, that surprised me. Even for plants that only are in cultivation for a short period. I have asked several sources where specific plants came from and it seems there is a distinct lack of interest where the plants come from. I know many collectors of all sorts of genera and they all document where they got their plants from so why do so few Pleione collectors?.
As for "Confirmation" versus x lagenaria. Lagenaria originates from Assam, a place where very few wild material comes from (independent of genus), certainly not in recent years, and I only guess the original introduction can be traced back to the years of Kingdon-Ward. Because both the parents are quite variable and widespread any remade cross would look different. A Chinese maculata x a Indian praecox would produce different variation than a Thai maculata x Chinese praecox. Ian Butterfield has both separately in his list but how can he keep them apart unless he knows the origin of his lagenaria? He got bulbs of "Confirmation" from the widow of the late maker of this hybrid (Jan Berg) directly so I am sure his "Confirmation" is correct. Any plant that can be traced back prior to the Jan Berg remake would likely (but not with 100% certainty) be true lagenaria. And that would also apply to the other hybrids, if the stock predates the manmade hybrid it would increase the possibilty it is the natural hybrid.
A "first" introduction is only done once and generally with few bulbs so the variation of a first introduction of a natural hybrid would initially be limited, certainly with hybrids of which the parents are rare. Of course not x barbarae which was introduced en masse and seems to form large stable populations in the wild. But a hybrid like x confusa I would imagine would be rare, even in the wild as one of the parents is rare so overlapping geographic distribution would be limited. Maybe Paul Cumbleton can tell how variable his x "Cuxius" was? Primary hybrids generally tend to be quite uniform in their offspring.
But apart from the question if they can be bought with a reliable pedigree, do we know all 6 were actually introduced in cultivation, even if that was only once? I haven't got the Butterfield book yet, is that mentioned in the book?
Therefore I am hoping that someone knows for certain where pedigree natural material can be obtained directly retraceable to the wild, either through recent imports from China or to the original introduction many years ago. Probably a needle in a hay stack but I am not interested in manmade hybrids, only natural hybrids.
Paul Christian I find a doubtful source as he assumes too much without having the in-depth knowledge of specific genera (and often can't even get the proper names and notation right)