Peter,
I hate to tell you this, but neither of those plants are true species plants.
In Thailand, like in Japan, the species concept is somewhat fluid. If it looks like 'X', they call it 'X' (same as the Japanese do with Neofinetia falcata and it's hybrids).
There are two key identifiers for V. coerulea:
#1: The petals twist 180 degrees, and present the backside to the viewer.
#2: The leaves are very short, so the plant is very slender (rarely more than max 30 cm across).
I have held this view for years. About 4 months ago, I had an opportunity to discuss it with Dr. M. Motes, who confirmed my suspicions.
Any blue Vanda with strong tesselation, and non-twisting petals, is with 100% certainty a hybrid.
According to Dr. Motes, this has been confirmed by DNA analysis done somewhere in Asia (he did not give me the nationality of the researcher).
It is difficult to point fingers at anyone for this situation:
- In Thailand, a blue Vanda is a blue Vanda.
- And, unless someone has been involved with orchids as long as I have, most traders/resellers simply don't know any better.
I was doing a webinar for the AOS last Saturday. Two of the slides in my presentation were these: