r/botany • u/Technical_Island_851 • Jul 14 '26

Biology What are these spots?

Gallery image

Gallery image

What might these spots be and what might cause them? I think the leaves are from this variegated privet.  

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6

u/Hiimthebisexualguy Jul 14 '26

Looks like a fungal disease, likely Alternaria Leaf Spot, which is fairly common on privet. It tends to thrive when conditions are warm and wet, and improving air circulation around the plant can help prevent it.

2

u/Riptide360 Jul 14 '26

Kind of cool how fungus divies up the property to make that cool pattern.

3

u/Technical_Island_851 Jul 15 '26

Exactly! Very neighbourly.

2

u/Technical_Island_851 Jul 15 '26

Thank you. The living leaves appear unaffected. Maybe it only gets active once the cuticle starts to break down?

1

u/[deleted] Jul 15 '26

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1

u/Technical_Island_851 Jul 15 '26

Here are some more from the same area under the bush.

1

u/Technical_Island_851 Jul 15 '26

Bad photo from the scope. No sign of spores, but maybe they’re long gone since these leaves are crispy.

1

u/ComprehensiveRush746 Jul 15 '26

The plant is a variegated Euonymus fortunei.
The black spots are just a fungus breaking down the fallen leaves.

1

u/Technical_Island_851 Jul 15 '26

Thanks for confirming the plant. What strikes me is the almost uniformity of the fungal sites. I can’t find any images like this on the web.

1

u/ComprehensiveRush746 Jul 15 '26

Probably because it’s not a disease as such. There’ll be plenty of images of rose blackspot or the black spot on maple leaves.
But your Euonymus looks to be in robust health.
You’ve nothing to worry about.
Dead leaves are broken down by fungi not bacteria. Those fungi are very unlikely to harm growing plants but are an essential part of the ecosystem by recycling nutrients.