Delimitation of Phakopsora, Physopella and Cerotelium and their species on Leguminosae

Two species are established for the soybean rust fungi based on morphological differences between their anamorphs and teleomorphs: Phakopsora pachyrhizi includes the Austro-Asian populations whose telia are irregularly 2- to 7-spore layered, and whose teliospores have walls that are pale yellowish brown to colourless, and equally ca 1 μm thick or slightly thickened apically to 3 μm in the outermost spores. Malupa sojae (syn.: Uredo sojae ) is its uredinial anamorph. Phakopsora meibomiae includes the New World populations whose telia are irregularly 1- to 4(−5)-spore layered, and whose teliospores have walls that are cinnamon- to light chestnut-brown, and 1·5–2 μm thick but thickened apically to 6 μm in the outermost spores. Malupa vignae (syn.: Uredo vignae ) is its uredinial anamorph. Physopella is treated not as a teleomorph but as an anamorphic genus with connexions to Phakopsora and Cerotelium. Angiopsora is a teleomorphic genus for which Physopella was erroneously substituted. But Angiopsora is placed in synonymy under Phakopsora because its supposed defining characteristic of teliospores in vertical rows is not consistent. Malupa is named as a new anamorphic genus with sori that are surrounded by a peridium composed of one or more irregular layers of compressed and distorted hyphae ending in paraphyses. The spores are one-celled, usually echinulate, and usually sessile or almost so. The sori of Physopella are surrounded by numerous, well-defined paraphyses arising from the hymenial level, which are usually incurved over the sori. Cerotelium is separated from Phakopsora because its telial sori have a well-defined hymenium of teliosporogenous cells and hyaline, thin-walled teliospores, traits lacking in Phakopsora . In addition to two species on soybeans, four other species of Phakopsora and five species of Cerotelium parasitize legumes, each of which has either a Malupa, Milesia or Physopella anamorph. Three new unconnected Milesia species are included. All of these taxa occur on the subfamily Faboideae except two which are on Bauhinia in the Caesalpinioideae.