Native Guava: On the Brink of Extinction The once-thriving Native guava (Rhodomyrtus psidioides) is now teetering on the edge of extinction. A critically endangered species, it has been heavily impacted by the invasive myrtle rust, a fungal pathogen that has decimated its population. Myrtle Rust: The Silent Killer Myrtle rust, introduced to Australia in 2010,