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Cedar apple rust gall

Gymnosporangium juniperi-virginianae


Cedar apple rust is an important fungal disease of apple in North America east of the Rocky Mountains. It can defoliate trees and blemish fruit making them unmarketable. The fungus requires two hosts, apple and eastern red cedar (Juniperus virginiana L.), to complete its life cycle. Spores produced on apple do not infect apple, but only cedar and spores produced on cedar infect only apple.


Woodland edge.


I assumed that this gall was caused by some kind of gall wasp but this is actually a fungus.

No species ID suggestions


KarenL 6 years ago

I'm sure it will too! It's pretty much impossible to eliminate anything with 8 acres especially as we garden organically! :)

craigwilliams 6 years ago

I have a hunch it'll be back.........
Good luck

KarenL 6 years ago

Thanks Craig! I found it fascinating that it requires 2 completely different host plants in order to complete it's life cycle. However, as we have planted a number of crab apples this year I think I am going to have to remove it!

craigwilliams 6 years ago

Great spotting. I have an admiring respect for this fungus. I'm sure if I were an apple grower, it might be a different story though.

Tennessee, USA

Lat: 35.90, Long: -86.96

Spotted on Nov 2, 2011
Submitted on Nov 2, 2011

Related spottings

Cedar Apple Rust Cedar-Apple Rust Cedar Apple Rust Cedar-Apple Rust (The disiese this fungus causes)

Nearby spottings

Unknown spotting Queen Anne's lace (seed-head) Common thistle Field mushroom