Cronartium flaccidum f.sp. flaccidum on Vincetoxicum hirundinaria: a. Uredinia; b. Urediniospores; c. Teliospore columns (telia); d. Telium consisting of an erumpent long column of strongly coherent teliospores; e. Teliospore column with germinated teliospores bearing curved phragmobasidia with basidiospores (arrowhead); urediniospores adhering to the column (arrows) indicate that the telia emerge from uredinia, as well as (f) the uredinial peridium under the host epidermis around the base of the teliospore column; (a, c by Julia Kruse; b, d, f from Klebahn 1914: 722; e from Dietel 1928: 43, after Tulasne, with permission from Duncker & Humblot GmbH).