What is a genus? That is the question that must be answered before we can explain what happened to Coelogyne, or rather, what happened to Dendrochilum. It is best to start our explanation with an example. Take the genus Cattleya. The first Cattleya to be described was C. labiata. A reasonable guess is that everything that looks like C. labiata is a Cattleya. That means that it should have large, floppy, pinkish-purple flowers with broad petals and a trumpet-shaped lip.
I am newly enrolled AOS student judge. I have often heard of complaining that Dendrochilum is now Coelogyne, because – “taxanomists need jobs” “botanists need to publish or perish hence the name changes” etc., I should say that it is often a popular form of bonding among orchidists to complain about name changes as if we lack brain cells to store new information. I do play along so as not to offend. However, my curiosity to know the real reason for the name change led me to your very informative and easy to read article. Thank you.