Anatomy of rockcress pseudoflowers caused by Puccinia consimilis

Arabis pulchra plants infected by the crucifer rust fungus (Puccinia consim ilis) develop pseudoflowers. These pseudoflowers are characterized by stems with short internodes and numerous closely spaced, bright yellow leaves co ated with a sweet sugary substance. Pseudoflowers do not resemble normal A. pulchra flowers. Pseudoflowers, leaves, and stems of A. pulchra plants inf ected with P. consimilis and true flowers, stems, and leaves of uninfected A. pulchra plants were fixed, embedded, sectioned, and stained using standa rd microtechniques. Epidermal, ground, and vascular tissues of true leaves, true petals, and pseudopetals were examined and compared for anatomic diff erences. Examination of anatomic characteristics revealed that pseudopetals are modified leaves.