It’s been a rainy week here in Los Angeles and I noticed these today. I’m not sure if they were there before the rain but I’m completely stumped on what they are.

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2 Answers 2


Cottony Maple Scale

In your picture it looks like the upper trunk is cherry and the trunk that is covered with this scale (an insect, no need to worry about your trees)looks like a different type of tree; do you know what it could be?

Can you find this scale on any other plants?

Please send a picture of the leaves and a close up of a glob that you've cleaned a bit to see an insect in the middle?

Hope this helps.


Check out Schizophyllum Commune. I'm fairly sure this is what it is. Bottomside should have gills, but in the picture they are very young. Look at it from below or hold a mirror under it. It's a saprotrophic fungus. Once it has taken hold, there's really nothing you can do to remove it, since every action to that end will likely also be detrimental to the tree, leading to a higher susceptibility to disease and pests, while we can't possibly see how far the fungus has spread inside, so we would never really be sure to have removed it all, and spore release will have made sure there are new entry points for the fungus to start it's cycle all over. Circle of life. It might take decades for your tree to succumb to this mushroom, or it might take only a few years, it's hard to say. Avoiding spores of this fungus would be a fool's errand since it's the most ubiquitous fungi in the world, and since fungi spores are ubiquitous in their own right, and if there's one thing life teaches, it's that life will find it's way!

If it is Schizophyllum, it will turn into a paper-thin scaling when dry, but plump right back into it's fluffy normal appearance after some rainfall. It can be a really beautiful fungus, especially in larger shelves, and holds promise of very high value in the fight against cancer. In fact, it is the mushroom with the most promise for it, yet, sadly, to my knowledge it is not being used as such today.

Research/source: about 5 years worth of study and hobby mycology in the fields of mushroom determination and foraging, mushroom cell culture and cultivation, medicinal use of mushrooms in the fight against neuroborreliosis, and the role of mushrooms in mythology and religion.

  • I have always heard that mushrooms will only form on decaying matter. Could this be an exception?
    – Evil Elf
    Sep 20, 2019 at 12:26
  • This is not true at all. Mushroom spores will germinate and infect whenever and wherever conditions are ideal. The conditions for mycelium to thrive will vary greatly for different mushroom species though, and for Schyzophyllum it is wet/damp weather, and preferably in wood, but an interesting side note to this most common of all mushrooms, is that it is even known to have colonized several human beings, with one known instance of a fruit body appearing inside the bronchial region. Most often this happens to immunocompromised individuals. edit: nostril cavity was wrong, it was the bronchial r Sep 20, 2019 at 21:28
  • source: Schizophyllum commune: an unusual agent of bronchopneumonia in an immunocompromised patient, a case report by VIVIAN TULLIO*, NARCISA MANDRAS*, GIULIANA BANCHE*, VALERIA ALLIZOND*, ESTER GAIDO$, JANIRA ROANA*, ANNA MARIA CUFFINI* & NICOLA A. CARLONE* *Department of Public Health and Microbiology, University of Turin, Turin, and $Microbiology Laboratory, S. Giovanni Battista Hospital, Turin, Italy Sep 20, 2019 at 21:32
  • One more remark that I do must add for the sake of a complete answer, is that mushroom mycelium does cause a decay of sorts to the matter they consume, since mushrooms basically turn the complex fabric of what they grow on into the simple building blocks it is made of, such as sugars from lignins and they use that as an energy source to build new mushroom mycelium and fruit bodies, so in a way, they do cause decay, but so does any tree or plant when it feeds the soil microbiome so it can in turn feed them. Decay and generation generally go hand in the mushroom and plant kingdoms. Sep 20, 2019 at 21:41
  • This is officially my favorite post on the site ever. Such a great example of the knowledge that is quickly brought to the surface coming from great people.
    – Evil Elf
    Sep 21, 2019 at 1:55

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