Sunburn or Infection?

[DesignerofBeauty]

I was gifted a bunch of orchids from a late member of my orchid society. Is this just sunburn?

[Roberta]

The black spots look to me more fungal or bacterial... but also look fairly old. If dry, likely not an issue other than aesthetic. To determine whether they are spreading, consider drawing around them with a Sharpie, and then just keeping an eye on the plant. If the spots don't get bigger, whatever the problem was, it isn't there any more. Damage doesn't go away, but eventually old leaves drop (though you may need to wait a few years... don't cut otherwise healthy leaves, which the plant needs for photosynthesis.)

You should keep these "bequest" plants away from the rest of your collection until you have a chance to observe them for awhile. If those were mine, I'd also be purchasing some virus test kits to check any that look suspicious - it is a potential issue with legacy collections.

[JScott]

Roberta pretty much covered it, just wanted to say that I agree that it is not sunburn.

[DesignerofBeauty]

I figured it was bacterial/fungal, but was trying to be optimistic that it was something else . A lot of the orchids I received are in poor condition. They were left in a greenhouse for a while after he passed, and his wife was the only person able to care for them.

I am soaking the plants in individual bowls of superthrive and keeping humidity high. Hopefully I can save some! Thank you for your advice, I will order testing kits soon.

[estación seca]

Given that sad history, there is a high likelihood of sunburn, dessication and spider mite infestation. Be on the lookout.