Violet Rust

Puccinia violae

Puccinia violae (Phragmidium violaceum) is a plant pathogen native to Europe, Africa, and the Middle East. It primarily infects ''Rubus'' species.
Violet Rust (Puccinia violae) In a mixed forest understory, growing on Viola sororia. Murray County, GA, US. April 2021.
I may or may not have squeed a little over this one. A first for me! 
https://www.jungledragon.com/image/111768/violet_rust_puccinia_violae.html
https://www.jungledragon.com/image/111769/violet_rust_puccinia_violae.html Geotagged,Phragmidium violaceum,Spring,United States

Distribution

It has been used in the biological control of invasive blackberry species in Chile, Australia, and New Zealand. In 2005, it was discovered growing on Himalayan blackberry plants in Oregon. This accidental introduction does not appear to be infecting native vegetation, so it offers hope for reducing the impact of invasive blackberries in the Pacific Northwest.

References:

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Taxonomy
KingdomFungi
DivisionBasidiomycota
ClassPucciniomycetes
OrderPucciniales
FamilyPhragmidiaceae
GenusPuccinia
SpeciesP. violae