Spotting on Underside of Phaius Leaves?
 

I would have thought this was bruises from overhead watering or something, but the spotting only appears on the underside of the leaves. Has anyone seen this before?

Thanks!

Try wiping the leaves with a wet tissue - if you get red streaks, spidermites. It might be spidermites anyway... they hide on the underside of leaves, and LOVE to attack soft-leaved plants. You can spray the undersides of the leaves (tops too) with soapy water and/or rubbing alcohol for a start, but if it is spidermites, stronger measures (a miticide) are needed.

No red streaks - there doesn't seem to be anything to wipe away. The spotting is part of the leaf, a lot like the spotting that shows up on Oncidium leaf-tips if you know what I mean?

So maybe fungal (a spray-down with Physan might be useful) Where do you grow the plants? (Inside, greenhouse, outside?) If the last, where do you live? Someone who lives in similar conditions can then jump in.

The camera hasn't focused properly onto the spotted regions - slightly blurred.

Are the spots black-coloured? Or some other colour?

And do you have some gentle air-movement in the growing area?

Are you sure this isn't normal? I don't know this plant. The rest of the leaves look healthy.

Could it possibly be a nutrient issue? My other plants tend to let me know when they need more of a certain nutrient by the coloring of their leaves.

I checked my pair of Phaius and did not see this.