The Orange Octopus
A gall known as Gymnosporangium juniperi-virginianae is the plant pathogen that causes cedar-apple rust.
In virtually any location where apples, crabapples and eastern red cedar coexist, cedar-apple rust can be a destructive or disfiguring disease both of cedars and apples.
This gall has a very complex, two-year life cycle, and I’ve attached an article that goes into detail, if you should so desire to read: cedar-apple_rust_05-01-08r
Spores called teliospores are produced in the orange-colored gelatinous spore horns or tendrils. As the teliospores germinate, they produce another type of tiny spore, called a basidiospore. Basidiospores are released and carried by wind and driving rain to newly emerging leaves of the host tree species.
As many as 7.5 million basidiospores may be produced in a single gall. These spores have been shown to be carried as far as six miles. Once the spores land on the emerging host leaves, they germinate and infect the leaves when they are wet. I took these “prime time” photos during a 4/6/17 rain event, at a location in Prince George’s County, MD.