Thekopsora areolata . a–d. On Picea abies: a. Cone with aecia on adaxial side of the cone scales; b. Single cone scale with aecia; c, d. Aeciospores in SEM: c. view into an aecium after manually opening the peridium, showing the apical smooth caps of the spores; d. Chains of aeciospores; every aeciospore with a longitudinal smooth overlay connecting apex and base on one side; e–f. On Prunus padus: e. Light-brown hypophyllous uredinia in a small purplish leaf spot; f1, f2. Intraepidermal teliospores in surface view and vertical section; (a from Dietel 1928: 39, with permission from Duncker & Humblot GmbH; c, d from Zwetko and Blanz 2018: 276; f from Fischer 1904: 464, as Pucciniastrum padi, with permission from Bryolich).