Mike, you are correct in that species have been crossed to superior hybrids or other species and then crossed back once or more to create what looks like a superior species.
Neofinetia falcata is a good example with the Japanese calling certain plants with Ascocentrum, Vanda and other genera in the parentage a Neo. falcata. Another example, is Vanda coerulea that very hard indeed to certify as a true species in many cases in SE Asia.
Paphs, well its happening there too and thats a certainty.. I suspect that thaianum out of Taiwan suffer this fate too. While the species has been around for several decades before it was named (it was thought to be an inferior niveum and largely ignored), I see many very well shaped thaianum around in Taiwan that just look too large and too round for line breeding just yet. I cant prove it, but I am not trusting it.
I agree, this practice is disgraceful and I wish genetic testing were cheaper to shame a few breeders I could point a finger at.
Brett
Completely agree... For the thaianums, I have seen many in bloom in Thailand, from many growers, and none equals the round, big shape medium size plants of the Taiwan stuff indeed... Either the 2 nurseries that have such plants have bene lucky in Taiwan, or they both made the cross with niveum...
The other problem being the populations, and sometimes we split after the plants have been described as a single species. there has been phal bellina and violacea, there is now dendrobium nobile and linawianum ( quite a lot of linawianum and nobile on the market are hybrids now...), dendrobium crepidatum and the undescribed white flowered species named 'crepidatum album', some of the dendrobium moniliforme with pinkish flowers have been split, and many moniliforme from Japan are in fact Xth generation hybrids with vastly different species, especially the big, full flower colored forms.
I am very suspicious as well at dendrobium primulinum from seed, the 'selected strains'. There are many different types or species whatever one wants sold under the name dendrobium primulinum, the pink white lip, the pink yellow lip, the all pink flower, etc... To me they are different species clearly, even the plant habit is different, flower shape, size, etc... but they are crossed together to get some improved dendro. primulinum nowadays...
Rothschildianum starts too, I have seen some batches that are clearly William Ambler x roth. If you choose the right staminodium and flower shape, they cannot be told apart from a roth ( and I have a little experience with roths...). Same for the massive stonei from Taiwan, there are some strains that are complex stonei hybrids made by Rex van Delden about 30 years ago ( a crazy hybrids of stonei x Berenice if I remember correctly, they looked exactly like a stonei but very wide petals...), backcrossed onto good quality stoneis. It makes very beefy stonei nowadays.