Great Basin Naturalist


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