Cesar Calderon, USDA APHIS PPQ, Bugwood.org

dry bean rust (Uromyces appendiculatus) sign on bean (Phaseolus spp.)

Cesar Calderon, USDA APHIS PPQ, Bugwood.org

dry bean rust (Uromyces appendiculatus) asexual spore

David B. Langston, University of Georgia, Bugwood.org

Small, red to brown spots that coalesce, eventually covering a large portion of the leaf. Plant may defoliate.

Mary Ann Hansen, Virginia Polytechnic Institute and State University, Bugwood.org

dry bean rust (Uromyces appendiculatus) symptoms on bean (Phaseolus spp.)

Howard F. Schwartz, Colorado State University, Bugwood.org

Close-up view of the pycnium of bean rust (Uromyces appendiculatus).

Howard F. Schwartz, Colorado State University, Bugwood.org

Bean plants severely infested with rust (Uromyces appendiculatus).

M.A. Brick, Bugwood.org

Bean leaf showing symptoms of rust (Uromyces appendiculatus) in variety trials conducted by Colorado State University.

Howard F. Schwartz, Colorado State University, Bugwood.org

Telia of bean rust (Uromyces appendiculatus) on a bean leaf.

Howard F. Schwartz, Colorado State University, Bugwood.org

Bean leaves displaying the "green island effect" of bean rust (Uromyces appendiculatus).

Howard F. Schwartz, Colorado State University, Bugwood.org

Uredinia of bean rust (Uromyces appendiculatus) on the leaves of plants in the field.

Howard F. Schwartz, Colorado State University, Bugwood.org

Uredinia of bean rust (Uromyces appendiculatus) on plants, causing wilting of the bean canopy in the field.

Howard F. Schwartz, Colorado State University, Bugwood.org

Uredinia of bean rust (Uromyces appendiculatus) on a bean pod.

Howard F. Schwartz, Colorado State University, Bugwood.org

Telia of rust (Uromyces appendiculatus) on the stem of a bean plant.

Howard F. Schwartz, Colorado State University, Bugwood.org

Rust telia (Uromyces appendiculatus) on bean pods in the field.

Howard F. Schwartz, Colorado State University, Bugwood.org

Rust (Uromyces appendiculatus) reaction on the dry bean varieties UI126 and Bill Z.

Howard F. Schwartz, Colorado State University, Bugwood.org

Rust aecium (Uromyces appendiculatus) on the leaf of a volunteer dry bean plant.

Howard F. Schwartz, Colorado State University, Bugwood.org

Aecia and pycnia of bean rust (Uromyces appendiculatus) on the leaves and stem of a volunteer dry bean plant.

Howard F. Schwartz, Colorado State University, Bugwood.org

Aecia of bean rust (Uromyces appendiculatus) on the stem of a dry bean plant inoculated in the greenhouse.

Howard F. Schwartz, Colorado State University, Bugwood.org

Telia of bean rust (Uromyces appendiculatus) on the leaf of a bean plant.