Phragmidium violaceum

Species infecting living leaves of Rubus sp. (brambles), producing small purplish spots on the upper leaf surface and powdery lemon-yellow to orange pustules on the lower surface corresponding to uredinia, which develop into dense black crusts corresponding to telia (the stage preceding basidium formation).

Uredinia surrounded by a peripheral ring of hyaline, subcylindrical, clavate to pyriform paraphyses 45 to 60 µm long and 15 to 25 µm wide.

Urediniospores subglobose to ellipsoidal, 20 to 30 µm long, 18 to 25 µm wide, with a hyaline wall 3 to 5 µm thick, uniformly ornamented with fine warts or spines over the entire surface.

Teliospores cylindrical with rounded ends, dark brown, 60 to 85 µm long, 25 to 35 µm wide, with 2 to 4 thick transverse septa, thick-walled and slightly verrucose, with a hyaline pedicel 80 to 170 µm long, and a small conical hyaline apical papilla up to 3 to 4 µm high with a rounded tip.

Herbarium material available: JTP2520/25 and JTP2592/25.