Anyone knows what this is?
Some more tecnhical info on the grow please so we can help? Indoor, outdoor? lighting? how old is the plant and in which stage?watering schedule? medium? ph reading? what are your temperature and humidity readings? since when this happened? did you do anything particular for it to happen?
Is this only on these 2 leaves or over the whole plant?
My first guess would be powdery mildew but cannot confirm until i know more - If it is powdery mildew, then mix a teaspoon of baking soda, 1/2 teaspoon of washing liquid (or wetting agent) into 1 gallon of water. Then spray the affected area twice a day (only when lights are off). If the lady is flowering, then i would avoid spraying anything and just remove the affected leaves before it spreads even more.
Avoid spraying your plant during flowering.
But i repeat, i am not sure if it this one, could be another fungus.