Bulbophyllum Stramineum black spots on leaves
 

Hello everyone,
I just bought one week ago this orchid beside another Bulbophyllum(Rotchildinum)
When i woke up this morning I could noticed these black spots on its leaves, and one of its leaves turned yellow.
What can it be?
I must say that its grower divided it a day or two before he gave it to me(Can it be trauma?).
The weather is around 21c and i provide my orchids around 70% humidity till night.
The other orchid which got divided as well was the Rotchildinum which is totally fine, his leaves are green and it looks nice.
What could have gone wrong with the Stramineum?
Thank you!

How did your plant turn out? I have just experienced something similar and am a little stumped.

I'm sorry, I didn't see this question when posted in December 2021.

Bulbophyllum stramineum is now considered a synonym and the correct name is Bulbo. cummingii. You might find more information with that name.

The first thing I see is the plant is very dessicated and wrinkled. The leaves and pseudobulbs should be smooth and shiny when well hydrated. It is in large bark, and it is very dry. When Bulbos get dessicated they get large black spots, and entire growths may turn black. I think this is the problem with the plant in the picture. It looks like a rot but instead this is how Bulbos act when too dry.

Bulbos of all sizes have much thinner and shorter roots than other orchids. This means they take longer to absorb water than do many other orchids. They expect to be very moist to wet, and the roots should not dry out for any length of time. I wouldn't try to grow them in large bark; I prefer sphagnum moss, which I keep always wet. Some people grow them in fine bark. But the roots should always be moist.

If one had received a bulbo that was very desiccated and the leaf should do this after appropriate potting and providing ample moisture, what to do about it? Okay to wait for the leaf to fall off? Remove it? What about the pseudobulb it is attached to? It all a goner or can it recover in time?

A severely dessicated growth in any orchid sometimes will return to normal appearance with proper watering, and sometimes will not. More important will be whether new growth develops normally.

I don't remove old plant parts until they're completely dry and brown.

Okay. Thank you!