This rust disease, due to Puccinia Pruni-spinosce, occurs on practically all the stone-fruits, but in the United States it affects chiefly the plum. Certain stages in the development of the rust fungus are found on hepatica, anemone and thalic-trum, all common wild flowers. The trouble shows on the lower surface of the leaves of stone-fruits as small, round, powdery, yellowish brown pustules. Opposite these pustules, on the upper surface, the leaf turns reddish yellow in local areas. Such lesions frequently become limited and the affected tissue falls away, leaving a shot-hole effect in the leaf. These spots and holes may be confused with those caused by the California peach blight fungus (Coryneum Beijerinckii Oud.), but are distinguished from the latter by their smaller size. Peach rust has a rather general geographical range, but does not ordinarily do damage sufficient to warrant treatment. See also Plum, page 377, and Apricot, page 156.