Epitypification of Puccinia psidii, casual agent of guava rust

<em>Puccinia psidii</em> is an important pathogen considered a threat to plants of the Myrtaceae around the world. Morphological variability has created misunderstanding around the classification of this pathogen. Due to the obligately biotrophic nature of <em>P. psidii</em>, the age of the material on which the original description was based, and the poor condition of its DNA, there has been no clear genetic characterization of the species. An epitype is therefore designated for <em>P. psidii</em> for precise application of this taxon name. A morphological description and DNA characterization are provided from the epitype, obtained from the same location and host of the lectotype, also designated herein. Morphologically, the epitype is identical to the original material and phylogenetic and microsatellite analyses show that the epitype is representative of <em>P. psidii</em> from guava in Brazil.