Addendum:
Maybe the salt is just what is needed to stress an otherwise healthy plant
into blooming? Or maybe (in cultivation) the salt helps dry out the medium
for species that crave a hastily drying compost? I'm thinking Tolumnias
here, of course, bat also the Schomburgkias mentioned earlier.

Maybe (but this is a stretch) the layer of salt prevents the plants from
being burnt by excessive light?

Theories... Never get enough light here up in the north anyway. Am certainly
not in the place to theorize about it

I am going to post a link to a pic of the Tolumnia as I need it identified,
if anyone is interested in seeing it.

//H