Peanut rust, caused by Puccinia arachidis, appears as minute leafspots or flecks that are visible from both sides of the leaf. As the number of infections increase and become older, leaves become a “rusty” yellow color. Infections may also develop on stems and leaf petioles. Lesions viewed from the under surface of leaves will exhibit masses of reddish-brown spores that are easily spread by air movements to other leaves. These spores are capable of causing new infections and increasing the severity of disease.