Very nice and the picts are really excellent.

So, what's the difference between this one and D. cucullatum? Are they synonyms? I have one that came as D. aphyllum, but I was later told it was really perriardii. Its blooms were just like this one, pale pink with a flush of yellow, impossible to photograph. Then I was told that it was really cucullatum and that perriardii was just a syn. I know a few of you out there have this one - HELP!

D. cuculattum, D. perriardii and aphyllum are synonym. Sometimes is also called D. perriardii var. cuculatum.
Defenitely a specie difficult to photograph.
But another Dendrobium is very close but is a specie by itself : Dendrobium primulinum when it comes without yellow lip. A pict of D. primulinum without yellow in Thailand :

Good info Phillipe, but what is the currently accepted "correct" name?

Alright guys, I'm gonna add a little more confusion to the taxonomic mix (or is it mess?). I thought that primulinum, pierardii, aphylum and cuculatum were all synonyms. However, on Phillipe's advice I looked them up on my OrchidWiz. The OW says that pierardii, aphylum and cuculatum are synonyms (just like what Phillipe said!) and that primulinum is a separate species. However, the OW has many pics of what looks like pierardii with a big fat dark yellow throat (much like loddigessi, which I probably spelled wrong). So I'm wondering, which is it?

In fact Royal, they are synonym, so you an call any of the 3 names. But I think that the most ususally seen and used is aphyllum.
Oh yes , My god, Steve , that's always complicated with those species !
Try (TRY I wrote) to make clear from what I know :
That's a fact that D. aphyllum = D. pierardii = D. cucullatum. Then, D. primulinum is another different specie.
I have never seen aphyllum with "bright" yellow (only pale yellow) colour but primulinum comes with or without yellow throat and yellow colour can be "bright". It's very easy to get lost between aphyllum and primulinum. I have the 2 species and it was difficult to know "who is who'. But I found this answer in the book "a field guide to wild orchids of Thailand".
aphyllum : very light mauve sepal and petals, petals broader than dorsal petal, lip pale yellow with purples veins to the base.
primulinum : sepals and petals of about same width, light mauve. Lip yellow with purple veins.
I can add also that aphyllum has very fine canne and primulinum has thick canne.

I see! Thanks for the info!:bowing

Thanks Steve but I have to say that the real writer is Nantiya Vaddhanaphuti ( easy name to remember , isn't it ?:lol:), I just copy from the book I was talking about in previous post.
I found the pict I made where you can see differences between sizes of petals/sepals in the species we are talking about. In fact, I made those because I had exactly the same problem that you have to identify aphyllum and primulinum.
The first is D.primulinum with yellow throat.
The second is D.primulinum without yellow throat : sepals and petals and the same width.
The last is D.aphyllum with petals broader than dorsal petal.

Ahhh! Now its even easier to see! Cool, now I can tell the difference! Thanks!

Very elegant looking Steve! I love it!