The Genus Tranzschelia (Uredinales) in the Americas

Lopez-Franco, Rosa; Hennen, Joe

ABSTRACT: A defining character for Tranzschelia has been the presence of fascicled teliospores, but not all species produce them as previously reported. Fascicled and non-fascicled teliospores differ in their mode of development. A group of fascicled teliospores arises from a single sporogenous cell that buds-off several secondary sporogenous cells slightly asynchronously. Each secondary sporogenous cell then develops a single two-celled teliospore and pedicel. The pedicels tend to adhere and remain together. The pedicels are free at the upper part of the pedicel column and the teliospores usually break-off in this free portion. Non-fascicled teliospores arise from a sporogenous cell that buds-off a spore initial that forms the pedicel and an apical two-celled teliospore, but no secondary sporogenous cell is formed. In this case, a sporogenous cell does not begin a new spore until the previous one reaches a certain degree of maturation. The pedicel of the younger, much smaller spore does not adhere to the older one. Utilizing the fascicled and non-fascicled teliospore characteristic for grouping species, a revised description for the genus Tranzschelia and its species in the Americas is presented. Species with fascicled teliospores are: T. arthurii-macrocyclic, het- eroecious, spermogonia and aecia on Hepatica spp., uredinia and telia mostly on Prunus serotina subg. Padus; T. cohaesa-macrocyclic, autoecious, on Anemone spp.; T. discolor-macrocyclic, heteroecious, spermogonia and aecia on Anemone spp., uredinia and telia on Prunus spp., mostly subg. Amygdaliae; T. pulsatillae-microcyclic, on Anemone spp. subg. Pulsatillae; and T. thalictri-microcyclic, on Thalic- trum spp. Species with non-fascicled teliospores are: T. fusca-microcylic, on Anemone spp.; T. ornata sp. nov., described herein-macrocyclic, spermogonia and aecia unknown, presumably on Anemone spp., uredinia and talia on Prunus spp.; T. pruni-spinosae var. americana var. nov., described herein-macrocyclic, heteroecious, spermogonia and aecia unknown, presumably on Anemone spp., uredinia and telia on Prunus americana subg. Prunophora, and T. viornae-presumably macrocyclic, autoecious, spermogonia and aecia unknown, uredinia and telia on Clematis sp. subg. Viorna.