Part of my prep in doing research for my orchid presentations have come across this conundrum of genetic analysis for species identification and familial relationships. The need for the identification of true species is important to maintain the genetic stability of the wild population for the future and to determine taxonomic associations.
The problem we face is that the newer and bigger 'species' from line breeding and selection may be contaminated unknowingly or deliberately through the use of dubious parent species (like walkeriana 'Kenny' etc) and continued for generations, until one day it appears on the judging table as a superior species that has 0.5% hybrid genes. Through the use of genetic testing of certain SNPs, it may not be detected. So these can masquerade into the breeding population as pure. As David says, the entire genome may need to be analyzed through a comparison with a baseline of that species (extract from a confirmed jungle plant). It must take into account of the ploidy variability.
In the old days, certain species were thought to be one and the same and so were crossed with each other (such as violacea and bellinas, loddigesii and harrisonniana, etc). There are also different forms of the same species that may have been better off to separate like the different populations of trianae (typo vs sangretoro types), and were cross bred. Some were sold mistakenly as one species (eg guttata sold as tigrina) and bred onto a true tigrina, and perpetuated by breeders unbeknownst. These are the true infiltrators that can confuse the entire picture. I have seen plants of these in South America, posing as a species and being defended to the death of its authenticity by the owners.
As Geoff proposed, a systematic protocol of genotyping based on David's methods of full genome and SNPs analysis is the ideal way to truly identify a pure species from a mole. It is a costly endeavor but it is the only way. Cassio and Chase have led the initial stages to show the science has practical applications. It is now up to the universe pull this together as it did for barley lol.
I, for one, am ready to support this! Maybe we should start a crowdfund for this project.