Extract from Wikipedia article: Puccinia malvacearum, also known as hollyhock or mallow rust, is a species within the genus Puccinia known for attacking members of the family Malvaceae. An autoecious pathogen, it can complete its life cycle using a single host.
Blister-like pustules of hollyhock or mallow rust fungus (Puccinia malvacearum) on lower leaf surface of Geranium carolinianum on a lawn near apartments on George Bush Drive. College Station, Texas, March 11, 2019
Leaves of Geranium carolinianum with blister-like pustules of hollyhock or mallow rust fungus (Puccinia malvacearum) taken from a lawn near apartments on George Bush Drive. College Station, Texas, March 11, 2019
Blister-like pustules of hollyhock or mallow rust fungus (Puccinia malvacearum) on lower leaf surface of Geranium carolinianum taken from a lawn near apartments on George Bush Drive. College Station, Texas, March 13, 2019
Leaves of Geranium carolinianum with blister-like pustules of hollyhock or mallow rust fungus (Puccinia malvacearum) taken from a lawn near apartments on George Bush Drive. College Station, Texas, March 13, 2019
Blister-like pustules of hollyhock or mallow rust fungus (Puccinia malvacearum) on lower leaf surface and a stem of Geranium carolinianum taken from a lawn near apartments on George Bush Drive. College Station, Texas, March 13, 2019
Blister-like pustules on underside and yellow-orange sunken spots on upper leaf surface of Geranium carolinianum caused by hollyhock or mallow rust fungus (Puccinia malvacearum), taken from a lawn near apartments on George Bush Drive. College Station, Texas, March 13, 2019
Orange-brown bumps on underside of Geranium carolinianum leaf caused by hollyhock or mallow rust fungus (Puccinia malvacearum), taken from a lawn near apartments on George Bush Drive. College Station, Texas, March 13, 2019
Back lit leaf with blister-like pustules of hollyhock or mallow rust fungus (Puccinia malvacearum) on Geranium carolinianum taken from a lawn near apartments on George Bush Drive. College Station, Texas, March 13, 2019
Leaves of Geranium carolinianum with blister-like pustules of hollyhock or mallow rust fungus (Puccinia malvacearum) on a receding shore of Lake Conroe on Stubblefield section of Lone Star hiking trail north from Trailhead No. 6 in Sam Houston National Forest. Texas, February 16, 2020 Lone Star Hiking Trail, Montgomery, TX 77356, USA