Puccinia smyrnii

My thanks to Javier Marcos Martínez for providing the material for study.

On living petioles, stems, or leaves of Smyrnium olusatrum, causing bright yellow to orange galls; this study corresponds to the aecial stage of the species.

Aecia bowl- or cup-shaped, with a strongly raised and lacerate whitish margin; inside are the aeciospores of a very striking yellow color; these aecia measure only 0.5 to 0.7 mm in diameter, forming groups of numerous specimens, often arranged in circles.

Hyphae of the aecial wall (peridium) highly compacted, angular, hyaline, 25 to 40 µm long, 22 to 35 µm wide, with very thick and strongly verrucose walls 4 to 5 µm thick.

Aeciospores ellipsoidal to pyriform, yellow under the microscope, 27 to 35 µm long, 16 to 24 µm wide, with a distinctly verrucose wall 1.5 µm thick, and abundant granular yellow pigment inside, although this pigment tends to disappear upon dehydration.

Herbarium material available: JTP2455/25.