New species, names, and type designation of rust fungi from New Zealand

Rust fungi are obligate plant pathogens, usually restricted to a single host species or genus, although some species such as myrtle rust (Austropuccinia psidii) and some cereal and grass rusts (Puccinia spp.) can infect many members of the families Myrtaceae and Poaceae, respectively. The rust life cycle can involve up to five spore stages, both sexual and asexual. The cycle may be completed on a single host (autoecious rust) or require two, unrelated host plants (heteroecious rust) for completion. About 300 rust species are known in New Zealand, with approximately half comprising native rusts (usually pathogenic on native plants) and half being introduced rusts (usually pathogenic on exotic plants). In this paper, 26 new species of rust fungi discovered in New Zealand are described, comprising one species each of Aecidium and Milesina, two of Pucciniastrum, four of Uromyces and 18 of Puccinia. Puccinia ferocis-forsteri is a new heteroecious species producing uredinia and telia on the endemic Carex forsteri and aecia on endemic Urtica ferox. This is only the third native heteroecious rust fungus reported in New Zealand. In addition, two species are transferred to the genus Milesina, three to Uromyces and seven to Puccinia (including a nom. nov.), either following discovery of the sexual (telial) stage of these rusts or considering the most appropriate sexual genus. A new combination is proposed for Coleosporium based on morphology of its urediniospores and molecular data. Epitypes are designated for eight species, lectotypes are selected for five species and a neotype is designated. Apart from one new species on the introduced Fuchsia magellanica all the rusts are considered native to New Zealand. Where appropriate, DNA was extracted and the 28S region (nuclear large subunit ribosomal DNA [nuLSU]) was amplified with the resulting LSU sequences aligned with sequences from GenBank representing most of the major clades.