Phragmidium violaceum
species of fungus

Phragmidium violaceum is a plant pathogen native to Europe, Africa, and the Middle East. It primarily infects Rubus species.
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.
Symptoms
The foliar symptoms that can be found include purple leaf spots along with yellow and tan centers. These can be found on the upper surface of the leaf and can resemble Septoria leaf spot. On the lower surface of the leaf yellow to orange pustules will be surrounded by a purple tinge. These can resemble cane and leaf rust. The leaves that are severely infected can start to dehydrate as well as start to curl.
This brief starts where responsible research should: with the source description of “Phragmidium violaceum” as species of fungus. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the science & nature register because the source frames it as species of fungus. Its deeper value depends on whether names, dates, institutions and citations support that framing.
The date and method of observation matter as much as the stated conclusion, especially where classification or consensus has changed. The source revision retrieved here is dated Nov 19, 2025. The linked authority identifier is Q7188040. None of the 0 selected statements returned an explicit reference. The first chronological checks are 2005.
A general summary may omit uncertainty, sample limits or methodological disagreement that is explicit in the technical record. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
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This entry incorporates text from “Phragmidium violaceum” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.