What's wrong with my Epiphyllum Oxypetalum? The spots are not as visible in daylight as it looks on the picture. And you can't feel the spots on the leaves, it seems to be inside the leaf??
I have seen it on some of my plants, but I have not found out what it is. So far it does not appear to have caused any serious damage. It might have something to do with stress, it has appeared after cold and/or dry periods.
Thank you mandarin for your answer. In this case it could actually be stress, it may have got too cold for few days.