Gentiana orbicularis or Gentiana brachyphylla?

[t5247rb]

This pic was taken at 2820m on July 14 on a high alpine peak.  According to one website, there are two gentiana species which like this mountaintop habitat, Gentiana orbicularis and Gentiana brachyphylla but I have difficulty telling them apart.  Anyone have any advice?

[ranunculus]

Comparing your image with the two named gentians in Flora Helvetica I would certainly plump for Gentiana orbicularis (Rundblattriger Enzian).
G. brachyphylla (Kurzblattriger Enzian) has a longer flower tube (but the same overall height of plant), not completely circular leaves and the foliage appears a little less tightly congested....but (and this very much depends on where exactly you took your shot) there is also Gentiana schleicheri (Schleichers Enzian) to be taken into consideration....it doesn't get any easier, does it?

[t5247rb]

The location is Austria (Tirol).  I believe the rocks are siliceous.  Does that help?  According to a website source the leaves of Gentiana schleicheri are pointed which is why I ruled it out in this case.

[hadacekf]

It is Gentiana bavarica var. subacaulis. It is much dwarfer as G. bavarica. It has almost stemless flowers and broader imbricate leaves and grows above 2400 m in the Alps.