Meadowsweet rust gall on the petioles and / or midrib veins. The rust has a severe effect on the survival of meadowsweet seedlings. Meadowsweet rust gall Triphragmium ulmariae is a species of fungus in the Sphaerophragmiaceae family. It causes meadowsweet rust gall, which develops as a chemically induced swelling, arising from the lower surface of the meadowsweet leaves. This common gall is caused by the foliar 'rust' fungus "Triphragmium ulmariae" (DC.) Link, 1825 . The fungus attacks the petioles and / or midribs of the perennial meadowsweet ("Filipendula ulmaria") plant, a member of the family Rosaceae, causing swelling and distortion. Sori develop with
Rust for corrosion of iron and its alloys, such as steel. Many other metals undergo similar corrosion, but the resulting oxides are not commonly called rust. Other forms of rust exist, like the result of reactions between iron and chloride in an environment deprived of oxygen. Rebar used in underwater concrete pillars, which generates green rust, is an example. Although rusting is generally a negative aspect of iron, a particular form of rusting, known as "stable rust," causes the object to have a thin coating of rust over the top, and if kept in low relative humidity, makes the "stable" layer