Austropuccinia licaniae, first congeneric with the myrtle rust pathogen A. psidii.

In 1895 and 2001, rust fungi affecting Licania trees (Chrysobalanchaceae) in Brazil were described as Uredo licaniae by Hennings in the state of Goiás and as Phakopsora tomentosae by Ferreira et al. in the state of Amazonas, respectively. Recently, a Licania rust fungus collected close to the Amazonian type location sharing symptoms with the former two species was subjected to morphological examinations and molecular phylogenetic analyses using 28S nuc rDNA (ITS2-28S) and cytochrome c oxidase subunit III (CO3) gene sequences. Since the original type specimen of Ph. tomentosae is considered lost, we carefully reviewed the type description and questioned the identity of the telium, which justified the description of the fungus as a Phakopsora species. Furthermore, the additional revision of the type material described by Hennings revealed that Ph. tomentosae is a synonym of U. licaniae. Based on the morphological examinations, disease symptoms, and shared hosts, we concluded that the newly collected material is conspecific with U. licaniae. However, the phylogenetic analyses rejected allocation in Phakopsora and instead assigned the Licania rust fungus in a sister relationship with Austropuccinia psidii (Sphaerophragmiaceae), the causal agent of the globally invasive myrtle rust pathogen. We therefore favored a recombination of U. licaniae (syn. Ph. tomentosae) into Austropuccinia and proposed the new name Austropuccina licaniae for the second species now identified for this genus. The fungus shares conspicuous symptoms with A. psidii, causing often severe infections of growing leaves and shoots that lead to leaf necrosis, leaf shedding, and eventually to the dieback of entire shoots. In view of the very similar symptoms of its aggressively invasive sister species, we briefly discuss the current state of knowledge about A. licaniae and the potential risks, and the opportunity of its identification.

Cerradopsora, a new genus of neotropical rust fungi.

Two Cerrado rust fungi, Phakopsora rossmaniae and Aplopsora hennenii, described in 1993 and 1995 and originally assigned to families Phakopsoraceae and Ochropsoraceae, respectively, were subjected to molecular phylogenetic analyses using fragments of the nuc 28S and 18S rDNA and mitochondrial cytochrome c oxidase subunit 3 (CO3) gene. Although both taxa were morphologically well placed in their original genera, they were shown to belong in a strongly supported new lineage within the Raveneliineae distant from the Phakopsoraceae and Ochropsoraceae. Therefore, we properly treated this lineage as the new genus Cerradopsora now harboring C. rossmaniae (type species) and C. hennenii. However, this novel phakopsoroid genus remains in uncertain familial position without support to be included in any of the families that share space within the Raveneliineae.

Raveneliopsis, a new genus of ravenelioid rust fungi on Cenostigma (Caesalpinioideae) from the Brazilian Cerrado and Caatinga.

The multicellular discoid convex teliospore heads represent a prominent generic feature of the genus Ravenelia. However, recent molecular phylogenetic work has shown that this is a convergent trait, and that this genus does not represent a natural group. In 2000, a rust fungus infecting the Caesalpinioid species Cenostigma macrophyllum (= C. gardnerianum) was described as Ravenelia cenostigmatis. This species shows some rare features, such as an extra layer of sterile cells between the cysts and the fertile teliospores, spirally ornamented urediniospores, as well as strongly incurved paraphyses giving the telia and uredinia a basket-like appearance. Using freshly collected specimens of Rav. cenostigmatis and Rav. spiralis on C. macrophyllum, our phylogenetic analyses based on the nuc 28S, nuc 18S, and mt CO3 (cytochrome c oxidase subunit 3) gene sequences demonstrated that these two rust fungi belong in a lineage within the Raveneliineae that is distinct from Ravenelia s. str. Besides proposing their recombination into the new genus Raveneliopsis (type species R. cenostigmatis) and briefly discussing their potentially close phylogenetic affiliations, we suggest that five other Ravenelia species that are morphologically and ecologically close to the type species of Raveneliopsis, i.e., Rav. corbula, Rav. corbuloides, Rav. parahybana, Rav. pileolarioides, and Rav. Striatiformis, may be recombined pending new collections and confirmation through molecular phylogenetic analyses.

Reinstatement and phylogenetic allocation of the palm rust genus Cerradoa in the Pucciniaceae, and establishment of Pseudocerradoa, gen. nov.

The genus Cerradoa (type species Cerradoa palmaea) was established in 1978 by Hennen and Ono and named after the Brazilian Cerrado biome. The holotype collected in Planaltina, Federal District, Brazil, belonged to the first rust fungus reported on palms (Arecaceae). For decades, the status of Cerradoa as a distinct genus has been regarded as doubtful, representing a synonym of Edythea (Uropyxidaceae) starting with the second edition of the Illustrated Genera of Rust Fungi in 1983. Our molecular phylogenetic analyses, as well as our morphological investigations, allowed us to reject this synonymy, leading to the reinstatement of Cerradoa within the Pucciniaceae. Cerradoa, together with morphologically similar genera such as the newly established Pseudocerradoa with two species (Ps. paullula and Ps. rhaphidophorae) infecting araceous hosts, the fern rust Desmella, and also P. engleriana, could not be assigned to any of the seven identified major lineages within the Pucciniaceae. Edythea, instead of being maintained as a member of the Uropyxidaceae, was herein placed in Pucciniaceae, shown phylogenetically in close relationship to Cumminsiella mirabilissima, both infecting the Berberidaceae. Additionally, our extensive phylogenetic analyses add guidance for future taxonomic revisions in the highly polyphyletic genus Puccinia and other established taxa within the family Pucciniaceae.

New host associations and a novel species for the gall-inducing acacia rust genus Ravenelia in South Africa.

Trees in the genus Vachellia (previously Acacia) are commonly infected by the gall-inducing rusts Raveneliamacowaniana and R.evansii. Rust galls bearing aecial infections and relating uredinial and telial infections on the leaves of nine Vachellia species not previously recorded to be infected by Ravenelia spp. have recently been collected in South Africa. The rust fungi causing these infections were characterised using molecular phylogenetic analyses of DNA sequence data of the LSU and ITS rDNA regions as well as morphological examinations. The host range of R.macowaniana and R.evansii was thus re-assessed and extended from four to nine species and from one to three species, respectively. Application of Principal Component Analyses (PCA) of telial morphological characters provided evidence of an effect of the host species on the teliospore morphology in R.evansii, but only minor effects in R.macowaniana. A novel gall-inducing Ravenelia sp. closely related to R.macowaniana, was found on Vachelliaxanthophloea and it is described here as R.xanthophloeae.