Puccinia graminis

Free shipping. Made from 100% ring-spun cotton.

Four pustules of aecidia of Puccinia graminis, the Black Stem Rust Fungus, on the under side of a leaf of Berberis vulgaris, the Common Barberry. Each aecidium produced about 11,000 aecidiospores. Photographed by J. E. Howitt at the Ontario Agricultural College, Guelph. Magnified about three times.

Buller 1924.