Round fuzzy spots on Succulent

[jml95]

Hello everyone!

I am brand new to this forum and somewhat of a novice when growing succulents. About a month ago, on one of my succulents I noticed a few round fuzzy spots on a few of the leaves. I wiped them off with water and a brown cork-like circle is left. Even though the succulent seems to be doing fine, I was wondering if anyone knew what this was? Was it a fungus? Mold? Any insight would be greatly appreciated! Thanks!!

succulent.JPG (46.61 KiB) Viewed 855 times

[hegar]

Well, I may be way off base here, because I have not ever seen this phenomenon on a succulent. However, this reminds me of a fungus-alga symbiosis called Cephaleuros viridis. That organism only takes up a little space on its host and should not be a problem, unless the whole plant is covered.
The "lesions" are large, with a wavy (crenate) edge and the top is generally greenish or off white.

Harald

[jml95]

Thanks so much for your response! I looked up the algae you suggested and it just may be it. Although, as you alluded to, it may be difficult to say for sure since the only photos I could find were of leafy plants, not succulents.

I sprayed neem oil on one of the succulents "infected" with this and it hasn't returned. The other succulent got it back and before I even thought about taking a photo I sprayed with neem oil and also used it as a soil drench. This succulent also appeared to have scale, pretty much out of nowhere, on its stem. Could the circular fluff have been scale eggs? Its just so odd because the "infection" was almost perfectly round and when one looked close, it was almost mold-like in appearance with striations etc. Wierd. If it appears again...I will certainly take a photo and post. Hopefully it will be beneficial for us all! Thanks again!!

[hegar]

Hello jml95,
I did go and look for digital images of the lichen Cephaleuros virescens and found two decent shots of this fungus/alga symbiosis.
I am not convinced, that you do have this problem, because usually cacti are not kept in an environment that would lead to algal growth. However, take a look at my pictures.

Harald