Using citizen science to bridge taxonomic discovery with education and outreach.

PREMISE OF THE STUDY: Biological collections are uniquely poised to inform the stewardship of life on Earth in a time of cataclysmic biodiversity loss. Efforts to fully leverage collections are impeded by a lack of trained taxonomists and a lack of interest and engagement by the public. We provide a model of a crowd-sourced data collection project that produces quality taxonomic data sets and empowers citizen scientists through real contributions to science. Entitled MicroPlants, the project is a collaboration between taxonomists, citizen science experts, and teachers and students from universities and K-12. METHODS: We developed an online tool that allows citizen scientists to measure photographs of specimens of a hyper-diverse group of liverworts from a biodiversity hotspot. RESULTS: Using the MicroPlants online tool, citizen scientists are generating high-quality data, with preliminary analysis indicating non-expert data can be comparable to expert data. DISCUSSION: More than 11,000 users from both the website and kiosk versions have contributed to the data set, which is demonstrably aiding taxonomists working toward establishing conservation priorities within this group. MicroPlants provides opportunities for public participation in authentic science research. The project's educational component helps move youth toward engaging in scientific thinking and has been adopted by several universities into curriculum for both biology and non-biology majors.

Amplistroma gen. nov. and its relation to Wallrothiella, two genera with globose ascospores and acrodontium-like anamorphs.

Amplistroma is described as a new genus for A. carolinianum, A. diminutisporum, A. guianense, A. hallingii, A. ravum, A. tartareum and A. xylarioides. Species of Amplistroma are distinguished by large stromata of textura intricata with polystichous ascomata and long necks that are either erumpent from the stromatal surface or form bumps or protuberances. The type collection of Ceratostoma sphaerospermum was examined and found to be synonymous with Wallrothiella congregata. The distribution of W. congregata is expanded by collections from Costa Rica, the eastern United States and Puerto Rico. Wallrothiella congregata has ascomata that are long-necked and develop individually or are gregarious on the substrate but do not form large stromata. Amplistroma and Wallrothiella are distinguished by small asci with eight, minute, globose ascospores. An acrodontium-like anamorph occurs in both genera. Phylogenetic analyses of 28S large-subunit rDNA sequences group these taxa in a well supported clade distinct from known orders within the Sordariomycetidae but showing unsupported relationships with the Chaetosphaeriales and the Magnaporthaceae. Family Amplistromataceae is described for this clade and placed within the Sordariomycetidae incertae sedis.

A re-evaluation of genus Chaetomidium based on molecular and morphological characters.

Chaetomidium, a genus in the Chaetomiaceae, comprises 12 species that produce similar cleistothecial ascomata with a membranous, mostly pilose, peridium. Approximately six species of this genus produce some type of modified peridium composed of cephalothecoid plates that previous authors have hypothesized to be a homologous character within the genus. To better understand the phylogenetic affiliations of Chaetomidium and distribution of the cephalothecoid peridium within this genus we performed phylogenetic analyses with LSU, beta-tubulin and rpb2 sequence data. The results of these analyses showed that Chaetomidium is polyphyletic and should be restricted to its type, C. fimeti, and C. subfimeti. The remaining cephalothecoid and non-cephalothecoid species were scattered throughout the Chaetomiaceae and Lasiosphaeriaceae. The cephalothecoid species of Chaetomidium were distributed in three unrelated clades, suggesting that the morphological similarity amo'ng these particular species resulted from convergence instead of ancestry.

Two new genera in the Magnaporthaceae, a new addition to Ceratosphaeria and two new species of Lentomitella.

Ceratosphaerella is described as a new genus for C. castillensis and C. rhizomorpha. The genus is related to Ophioceras but distinguished by ascomata with a basal stroma and shorter, fusiform ascospores. Muraeriata is described for M. collapsa and M. africana, two species that are distinguished by having a vacuolate middle ascomal wall layer. The ascospores resemble those of Ceratosphaerella and ascospores in both genera are morphologically similar to those of Ceratosphaeria lampadophora. Both new genera are placed in the Magnaporthaceae based on LSU and SSU data. A species previously identified as Ophioceras tenuisporum was re-examined, found to fit the description of Pseudohalonectria phialidica and is transferred to Ceratosphaeria based on LSU data. Lentomitella tropica and L. pallibrunnea are described for two species that have long-necked ascomata with pale brown, ellipsoid ascospores and large ascal rings. Sequence data from the LSU places them in a clade with hyaline-spored Lentomitella crinigera and L. cirrhosa.

Development and dehiscence of the cephalothecoid peridium in Aporothielavia leptoderma shows it belongs in Chaetomidium.

The development of the cephalothecoid peridium of Aporothielavia leptoderma was examined using light and electron microscopy. Early stages in ascoma initiation were consistent with previous reports for other species in the Chaetomiaceae. However, as young cleistothecia increased in size, clusters of peridial cells in the outer textura angularis elongated in a radial pattern around a central cell or cell cluster to form rosettes of relatively thick-walled segments that marked the central areas of incipient cephalothecoid plates. The external flank along median portions of the radial cells became thin walled and swelled outwards so that each plate became concave and was separated from adjacent plates by a more or less circular to polygonal ridge of knuckle-shaped swellings. When dry, mature peridia split apart along some of the ridges demarcating individual plates but an internal mechanism for liberating ascospores from the confines of the ascoma was not observed. Physical disturbance of mature cleistothecia by beetles, when enclosed together in a Petri dish, shattered the peridia, liberating the ascospores. Smaller insects were unable to cause disarticulation of the cephalothecoid plates. Because of the presence of an apical germ pore in the ascospores and morphological similarity to Chaetomidium arxii, the new combination Chaetomidium leptoderma (syn. Thielavia leptoderma) comb. nov. is proposed.

Ascoma development and phylogeny of an apothecioid dothideomycete, Catinella olivacea.

Catinella olivacea is a discomycetous fungus often found fruiting within cavities in rotting logs. Because this habitat would lack the air currents upon which discomycete species normally rely for the dispersal of their forcibly ejected ascospores, we suspected an alternative disseminative strategy might be employed by this species. An examination of the development of the discomycetous ascomata in pure culture, on wood blocks, and on agar showed that the epithecium was gelatinous at maturity and entrapped released ascospores in a slimy mass. We interpreted this as an adaptation for ascospore disperal by arthropods. Developmental data also showed that C. olivacea was unusual among other discomycetes in the Helotiales (Leotiomycetes). For example, the ascoma developed from a stromatic mass of meristematically dividing cells and involved the formation of a uniloculate cavity within a structure better considered an ascostroma than an incipient apothecium. Furthermore, the ascus had a prominent ocular chamber and released its ascospores through a broad, bivalvate slit. These features, along with phylogenetic analyses of large subunit and small subunit rDNA, indicated that this unusual apothecial fungus is, surprisingly, more closely affiliated with the Dothideomycetes than the Leotiomycetes.

Leptographium piriforme sp. nov., from a taxonomically diverse collection of arthropods collected in an aspen-dominated forest in western Canada.

During a survey of fungi associated with arthropods collected in a southern boreal mixed-wood forest in Alberta we obtained 29 isolates of a unique species of Leptographium. This species displayed a distinct combination of characteristics, including curved conidia on short-stipitate conidiophores, a secondary micronematous conidial state, stalked pear-shaped cells and an optimal growth rate at 35 C, and is described as Leptographium piriforme sp. nov. The isolates were most similar morphologically to L. crassivaginatum, but ITS sequence comparisons indicate that our isolates cannot be assigned to this or any other sequenced species in the genus. Initial observations on the pear-shaped cells in feeding experiments with Sancassania berlesei show that these structures may act as a nutritional incentive for visiting arthropods. Most arthropods carrying this new species were caught in traps baited with dung which, in light of its optimum growth temperature, suggests a coprophilous phase in the life cycle of this species. Additional isolates from woody species typical of the survey area might clarify whether Leptographium piriforme in its forest habitat occurs as a plant pathogen or saprobe.

A functional interpretation of the role of the reticuloperidium in whole-ascoma dispersal by arthropods.

Auxarthron conjugatum (Onygenaceae) and Myxotrichum deflexum (Myxotrichaceae) are distantly related cleistothecial (gymnothecial) ascomycetes that form ascomata with strikingly similar peridia in which rigid, branched and anastomosed, thick-walled hyphae create a cage- or mesh-like enclosure (reticuloperidium). We tested the hypothesis that the reticuloperidium plays a role in dispersal mediated by arthropods by enclosing ascomata of these fungi together with flies from the family Sarcophagidae. Gymnothecia of both fungi were picked up easily when the stiff hairs of the flies impaled the ascomata by passing through the interhyphal spaces of the reticuloperidium. Ascospore release from the gymnothecia then occurred during grooming activities during which the limbs of the flies caught the ascoma appendages causing the peridium to be torn apart. This adaptation to arthropod morphology and behaviour is interpreted as the driving force behind the evolution of reticuloperidia in unrelated groups of cleistothecial ascomycetes.