P. toxicodendri Pileolaria brevipes, also known as poison ivy rust, is a species of autoecious fungus in the order Pucciniales.

[3] Poison ivy rust infections become evident in spring as "light pink to dark red swellings on leaflet veins or petioles.

The leaflet or leaf typically exhibits a curled morphology and oftentimes is wilted.

Individuals infected with P. brevipes are less prone to flower compared to adjacent, noninfected congeners".

[3] Damaging arthropod associates of Toxicodendron species include Epipaschia zelleri and the poison ivy sawfly.