L.L. Dreyer

New species of Ophiostomatales from Scolytinae and Platypodinae beetles in the Cape Floristic Region, including the discovery of the sexual state of Raffaelea

Olea capensis and Rapanea melanophloeos are important canopy trees in South African Afromontane forests. Dying or recently dead individuals of these trees are often infested by Scolytinae and Platypodinae (Curculionidae) beetles. Fungi were isolated from the surfaces of beetles emerging from wood samples and their galleries. Based on micro-morphological and phylogenetic analyses, four fungal species in the Ophiostomatales were isolated. These were Sporothrix pallida and three taxa here newly described as Sporothrix aemulophila sp. nov., Raffaeleavaginata sp. nov. and Raffaelea rapaneae sp. nov. This study represents the first collection of S. pallida, a species known from many environmental samples from across the world, from Scolytinae beetles. S. aemulophila sp. nov. is an associate of the ambrosia beetle Xyleborinus aemulus. R. rapaneae sp. nov. and R.vaginata sp. nov. were associated with a Lanurgus sp. and Platypodinae beetle, respectively, and represent the first Raffaelea spp. reported from the Cape Floristic Region. Of significance is that R.vaginata produced a sexual state analogous with those of Ophiostoma seticolle and O. deltoideosporum that also grouped in our analyses in Raffaelea s. str., to date considered an asexual genus. The morphology of the ossiform ascospores and anamorphs of the three species corresponded and the generic circumscription of Raffaelea is thus emended to accommodate sexual states. The two known species are provided with new combinations, namely Raffaelea seticollis (R.W. Davidson) Z.W. de Beer and T.A. Duong comb. nov. and Raffaelea deltoideospora (Olchow. and J. Reid) Z.W. de Beer and T.A. Duong comb. nov.

Thecaphora capensis sp. nov., an unusual new anther smut on Oxalis in South Africa

The smut genus Thecaphora contains plant parasitic microfungi that typically infect very specific plant organs. In this study, we describe a new species of Thecaphora from Oxalis lanata var. rosea (Oxalidaceae) in the Cape Floristic Region of South Africa. Molecular phylogenetic reconstructions based on large subunit ribosomal DNA sequence data confirmed the generic placement of the fungus and confirmed that it represents an undescribed species for which the name T. capensis sp. nov. is provided. The closest known sister species of the new taxon is T. oxalidis that infects the fruits of Oxalis spp. in Europe, Asia and the Americas. In contrast, T. capensis produces teliospores within the anthers of its host. This is the first documented case of an anther-smut from an African species of Oxalis and the first Thecaphora species described from Africa.

Development of polymorphic microsatellite markers for the genetic characterisation of Knoxdaviesia proteae (Ascomycota: Microascales) using ISSR-PCR and pyrosequencing

Knoxdaviesia proteae is one of the first native ophiostomatoid fungi discovered in South Africa, where it consistently occurs in the infructescences of the iconic Cape Biome plant, Protea repens. Although numerous studies have been undertaken to better understand the ecology of K. proteae, many questions remain to be answered, particularly given its unique niche and association with arthropods for dispersal. We describe the development and distribution of microsatellite markers in K. proteae through Interspersed Simple Sequence Repeat-Polymerase Chain Reaction (ISSR-PCR) enrichment and pyrosequencing. A large proportion of the 31492 sequences obtained from sequencing the enriched genomic DNA were characterised by microsatellites consisting of short tandem repeats and di- and tri-nucleotide motifs. Seventeen percent of these microsatellites contained flanking regions sufficient for primer design. Twenty-three primer pairs were tested, of which 12 amplified and 10 generated polymorphic fragments in K. proteae. Half of these could be transferred to the sister species, K. capensis. The developed markers will be used to investigate the reproductive system, genetic diversity and dispersal strategies of K. proteae.

Knoxdaviesia proteae is not the only Knoxdaviesia-symbiont of Protea repens.

Two polyphyletic genera of ophiostomatoid fungi are symbionts of Proteaceae in southern Africa. One of these, Knoxdaviesia, includes two closely related species, K. proteae and K. capensis, that have overlapping geographical distributions, but are not known to share Protea host species. Knoxdaviesia capensis appears to be a generalist that occupies numerous hosts, but has never been found in P. repens, the only known host of K. proteae. In this study, extensive collections were made from P. repens and isolates were identified using DNA sequence comparisons. This led to the surprising discovery of K. capensis from P. repens for the first time. The fungus was encountered at a low frequency, suggesting that P. repens is not its preferred host, which may explain why it has not previously been found on this plant. The basis for the specialisation of K. proteae and K. capensis on different Protea species remains unknown.

Bark and ambrosia beetles (Curculionidae: Scolytinae), their phoretic mites (Acari) and associated Geosmithia species (Ascomycota: Hypocreales) from Virgilia trees in South Africa

Bark and ambrosia beetles are ecologically and economically important phloeophagous insects that often have complex symbiotic relationships with fungi and mites. These systems are greatly understudied in Africa. In the present study we identified bark and ambrosia beetles, their phoretic mites and their main fungal associates from native Virgilia trees in the Cape Floristic Region (CFR) of South Africa. In addition, we tested the ability of mites to feed on the associated fungi. Four species of scolytine beetles were collected from various Virgilia hosts and from across the CFR. All were consistently associated with various Geosmithia species, fungi known from phloeophagous beetles in many parts of the world, but not yet reported as Scolytinae associates in South Africa. Four beetle species, a single mite species and five Geosmithia species were recovered. The beetles, Hapalogenius fuscipennis, Cryphalini sp. 1, and Scolytoplatypus fasciatus were associated with a single species of Elattoma phoretic mite that commonly carried spores of Geosmithia species. Liparthrum sp. 1 did not carry phoretic mites. Similar to European studies, Geosmithia associates of beetles from Virgilia were constant over extended geographic ranges, and species that share the same host plant individual had similar Geosmithia communities. Phoretic mites were unable to feed on their Geosmithia associates, but were observed to feed on bark beetle larvae within tunnels. This study forms the first African-centred base for ongoing global studies on the associations between arthropods and Geosmithia species. It strengthens hypotheses that the association between Scolytinae beetles and dry-spored Geosmithia species may be more ubiquitous than commonly recognised.

Reassessment of the taxonomic status of Oxalis fabaefolia (Oxalidaceae) and the description of a unique variety of Oxalis flava from the Northern Cape Province of South Africa

Jacquin (1794) also described another seemingly related group of species, O. asinina Jacq., O. crispa Jacq., O. fabaefolia Jacq., O. lanceaefolia Jacq. and O. leporina Jacq., and distinguished between them based on corolla colour, leaf shape and stylar morph type. Salter (1944) synonymised all of the species in this group under O. fabaefolia, placing O. asinina, O. lanceaefolia and O. leporina under O. fabaefolia Form B, but maintained O. fabaefolia and O. flava as separate species based on the presence of winged petioles in the former. He did, however, concede that certain forms of O. flava are scarcely distinguish- able from O. fabaefolia Form B. Abstract Southern African Oxalis taxonomy is complicated by tremendous morphological variation. The widely distributed Oxalis flava, for example, currently contains eight morphologically distinct forms. The remaining members of sect. Crassulae display morphological characters distinctive enough to retain specific status, despite resemblance to forms of the broadly defined O. flava. Recent collection of a taxon with strong morphological affinities to species in sect. Crassulae generated much interest. In this study we assess the placement of this new taxon to members of sect. Crassulae based on analyses of DNA sequence data of the Internal Transcribed Spacer (ITS) region and morphological comparisons. Results show that most members of sect. Crassulae are distantly related to O. flava. However, our morphological and molecular data strongly suggested that the newly collected taxon represents yet another form of O. flava. In addition, these data show O. fabaefolia to be nested within O. flava, suggesting that it should be synonymised under this broadly defined species. Both the new taxon and O. fabaefolia display unique morphological characters, allowing them to be considered separate subspecific taxa of O. flava. Thus the taxa O. flava var. fabaefolia and O. flava var. unifoliolata are here proposed.

Wounds on Rapanea melanophloeos provide habitat for a large diversity of Ophiostomatales including four new species.

Rapanea melanophloeos, an important canopy tree in Afromontane forests, is commonly utilised for medicinal bark harvesting. Wounds created from these activities provide entrance for many fungi, including arthropod-associated members of the Ophiostomatales and Microascales (ophiostomatoid fungi). In this study we assessed the diversity of wound-associated Ophiostomatales on storm-damaged R. melanophloeos trees in the Afromontane forests of South Africa. Five species were identified based on micro-morphological and molecular phylogenetic analyses. These included Ophiostoma stenoceras and four newly described taxa Sporothrix itsvo sp. nov., S. rapaneae sp. nov., S. uta sp. nov. and O. noisomeae sp. nov. Four of these are members of the S. schenckii–O. stenoceras complex (O. stenoceras, S. itsvo sp. nov., S. rapaneae sp. nov., S. uta sp. nov.) while O. noisomeae groups basal in the Ophiostomatales alongside the S. lignivora complex and Graphilbum. In addition to other taxa known from this host, the present study shows that there is a rich, yet still poorly explored, diversity of Ophiostomatales associated with R. melanophloeos in Afromontane forests. More taxa are likely to be discovered with increased research effort. These must be assessed in terms of pathogenicity towards this ecologically and economically important tree.

Two new Oxalis species ( Oxalidaceae ) from the Ai-Ais / Richtersveld Transfrontier Park, South Africa

South Africa has a rich, but scantily surveyed, desert flora. Documenting annual and geophytic species in this biome is challenging, as they usually only flower after adequate precipitation, which is characteristically erratic and infrequent. Recent floristic surveys in the Ai-Ais / Richtersveld Transfrontier Park were conducted after abnormally high precipitation and revealed the presence of numerous potentially new plant taxa, including two new members of the genus Oxalis. These taxa are clearly morphologically distinct from any known species. Here we explore the relationships of these species to other southern African species based on analyses of Internal Transcribed Spacer (ITS) and trnS-trnG DNA sequence data. Molecular data and morphological comparisons show that these collections represent new species closely allied to Oxalis pes-caprae, O. compressa, O. copiosa and O. haedulipes. Accordingly we describe them here as O. petricola and O. rubricallosa. Oxalis petricola is known from one isolated population of fewer than 500 individuals and is probably of special conservation concern. Oxalis rubricallosa is known from two small populations. The belated discovery of a large and showy species such as O. rubricallosa highlights the urgent need for more extensive floristic surveys of southern African desert regions.

Two new Sporothrix species from Protea flower heads in South African Grassland and Savanna

The inflorescences and infructescences of African Protea trees provide habitat for a large diversity of Sporothrix species. Here we describe two additional members, Sporothrix nsini sp. nov. and Sporothrix smangaliso sp. nov., that are associated with the infructescences of various Protea species from grasslands and savannas in the KwaZulu-Natal, North-West, Gauteng and Mpumalanga provinces of South Africa. Their description raises the number of described Protea-associated Sporothrix species to twelve. S. smangaliso sp. nov. is distantly related to other Protea-associated species and, in phylogenies using multiple markers (ITS, beta-tubulin and calmodulin), groups with taxa such as Sporothrix bragantina from Brazil and Sporothrix curviconia from the Ivory Coast. S. nsini sp. nov. resolved as sister to a clade containing four other Protea-associated species within the Sporothrix stenoceras complex. S. nsini sp. nov. was collected from within the same infructescences of Protea caffra that also contained the closely related S. africana and S. protearum. This highlights the need to study and understand the factors that influence host selection and speciation of Sporothrix in this atypical niche.

New relatives of Oxalis pes-caprae (Oxalidaceae) from South Africa.

The genus Oxalis in southern Africa contains more than 200 species, with the vast bulk of species in the Greater Cape Floristic Region (GCFR). Recent fieldwork has suggested that many await discovery. Here we investigate the identity of two apparently undescribed Oxalis species from Northern Cape, South Africa, using morphological comparisons with closely related taxa. We provide a preliminary phylogenetic placement using DNA sequence-based analyses of the Internal Transcribed Spacer (ITS) region. Both putative new species are distinguished from all known Oxalis species based on macro-morphological traits. Molecular data placed both within a clade consisting of the weedy O. pes-caprae and its close relatives. Oxalis hirsutibulba sp. nov. is characterised by densely hairy bulb tunics, a trait absent from all known members of the O. pes-caprae clade. Oxalis fenestrata sp. nov. is unique in producing apple green succulent stems and leaflets usually with translucent white markings at their incisions. We also provide the first phylogenetic placement of the GCFR narrow endemic O. lasiorrhiza in the O. pes-caprae clade. In conjunction with several other recent discoveries, these two new species and the phylogenetic placement of O. lasiorrhiza show that the O. pes-caprae clade is much more speciose than previously estimated.