Puccinia malvacearum

A parasitic fungus affecting living leaves or stems of Malvaceae; the specimens used for this study were collected on Malva sylvestris, Malva neglecta, and Alcea rosea, causing orange-yellow spots on the upper leaf surface and hemispherical grain-like pustules on the underside, orange-brown to dark brown.

Teliospores ellipsoidal to fusiform, two-celled, with a central septum and slight constriction at the septum, pale yellow under the microscope, 45 to 85 µm long, 14 to 21 µm wide, wall thickness 1 to 4 µm, with an apical thickening of 5 to 10 µm, and a long hyaline pedicel, thin-walled, 70 to 120 µm long.

From the germ pore of these teliospores, a hyaline basidium emerges with 4 transverse septa that will give rise to basidiospores.

Basidiospores ellipsoidal to amygdaliform, smooth, hyaline, thin-walled, 11 to 14 µm long and 9.5 to 10 µm wide.