Unroughing the cat's tongue mushrooms: Four new species of Pseudohydnum from Brazil based on morphological and molecular phylogenetic evidence.

Pseudohydnum, commonly known as cat's tongue mushrooms, is a monophyletic assemblage within Auriculariales, which encompasses species with gelatinous basidiomata, spathulate, flabellate, or shell-shaped pileus, hydnoid hymenophore, globose to ellipsoidal basidiospores, and longitudinally cruciate-septate basidia. According to the available literature, 16 species have been described in Pseudohydnum, mostly represented in temperate-boreal forests of the Northern Hemisphere. However, the limited morphological, molecular, and ecological information, especially from the Southern Hemisphere ecosystems, does not presently allow a reliable assessment of its taxonomic boundaries nor provide a complete picture of the species diversity in the genus. In an ongoing effort to examine specimens collected in dense and mixed ombrophilous forest fragments (Atlantic Rainforest domain) from Southeastern and Southern Brazil, additional taxa assigned to Pseudohydnum were identified. Four new species are recognized based mostly on characters of the pileus surface, stipe, hymenium, and basidiospores. Molecular phylogenetic analyses based on nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS barcode), partial nuc rDNA 28S, and partial RNA polymerase II largest subunit (RPB1) sequences supported the description of these new taxa. Here, we propose Pseudohydnum brasiliense, P. brunneovelutinum, P. cupulisnymphae, and P. viridimontanum as new species. Morphological descriptions, line drawings, habitat photos, and comparisons with closely related taxa are provided. A dichotomous key for identification of currently known Southern Hemisphere Pseudohydnum species is presented.

Phylogenetic and morphological re-evaluation of Camptophora.

The genetic variety and habitats of Camptophora species, generally known as black yeast, have not been clarified. In this study, we re-evaluated Camptophora based on morphological observations and phylogenetic analyses. Because prior investigations on Camptophora only included a few strains/specimens, 24 Camptophora-related strains were newly obtained from 13 leaf samples of various plant species to redefine the genetic and species concepts of Camptophora. Their molecular phylogenetic relationships were examined using small subunit nuclear ribosomal DNA (nSSU, 18S rDNA), the internal transcribed spacer (ITS) rDNA operon, the large subunit nuclear ribosomal DNA (LSU, 28S rDNA), ß-tubulin, the second largest subunit of RNA polymerase II (rpb2), and mitochondrial small subunit DNA (mtSSU). Single- and multi-locus analyses using nSSU-ITS-LSU-rpb2-mtSSU revealed a robust phylogenetic relationship among Camptophora species within Chaetothyriaceae. Camptophora species could be distinguished from other chaetothyriaceous genera by their snake-shaped conidia with microcyclic conidiation and loosely interwoven mycelial masses. Based on the results of phylogenetic analyses, two undescribed lineages were recognized, and Ca. schimae was excluded from the genus. ITS sequence comparison with environmental DNA sequences revealed that the distribution of the genus is restricted to the Asia-Pacific region. Camptophora has been isolated or detected from abrupt sources, and this was attributed to its microcycle. The mechanisms driving genetic diversity within species are discussed with respect to their phyllosphere habitats.

Airborne DNA reveals predictable spatial and seasonal dynamics of fungi.

Fungi are among the most diverse and ecologically important kingdoms in life. However, the distributional ranges of fungi remain largely unknown as do the ecological mechanisms that shape their distributions1,2. To provide an integrated view of the spatial and seasonal dynamics of fungi, we implemented a globally distributed standardized aerial sampling of fungal spores3. The vast majority of operational taxonomic units were detected within only one climatic zone, and the spatiotemporal patterns of species richness and community composition were mostly explained by annual mean air temperature. Tropical regions hosted the highest fungal diversity except for lichenized, ericoid mycorrhizal and ectomycorrhizal fungi, which reached their peak diversity in temperate regions. The sensitivity in climatic responses was associated with phylogenetic relatedness, suggesting that large-scale distributions of some fungal groups are partially constrained by their ancestral niche. There was a strong phylogenetic signal in seasonal sensitivity, suggesting that some groups of fungi have retained their ancestral trait of sporulating for only a short period. Overall, our results show that the hyperdiverse kingdom of fungi follows globally highly predictable spatial and temporal dynamics, with seasonality in both species richness and community composition increasing with latitude. Our study reports patterns resembling those described for other major groups of organisms, thus making a major contribution to the long-standing debate on whether organisms with a microbial lifestyle follow the global biodiversity paradigms known for macroorganisms4,5.

Suillus hypogaeus: First record of a truffle Suillus.

Suillus (order Boletales) is a diverse genus of epigeous, mushroom-forming fungi native to temperate forests across the Northern Hemisphere; however, some species are also present in areas where Pinaceae has been introduced in the Southern Hemisphere. Unlike the closely related genus Rhizopogon, there are no described hypogeous, sequestrate species of Suillus. Here, we describe Suillus hypogaeus, the first known species of the genus with hypogeous, sequestrate sporocarps. Collections were made on Marys Peak in Benton County, Oregon, USA, at an elevation of 800 m in forests dominated by Pseudotsuga menziesii var. menziesii. The peridium is white, quickly staining pink to purple-reddish where bruised or cut. The gleba is pale yellow when young, becoming purple with maturity, and the basidiospores are obovoid, light yellow in KOH, and amyloid in Melzer's reagent. Multilocus molecular phylogenetic analyses support the placement of S. hypogaeus among the Larix specialists in the spectabilis group of Suillus. Although Larix and Pseudotsuga are sister genera, Larix does not occur on Marys Peak or elsewhere in western Oregon. Suillus hypogaeus, therefore, represents both an independent origin of the hypogeous, sequestrate sporocarp within the Boletales and an independent host shift between Larix and Pseudotsuga within the genus Suillus.

New species of Chalciporus and Tylopilus from India, with keys to the known species.

Two new species, Chalciporus rubrostipitatus and Tylopilus purpureus, are proposed from India based on morphological and molecular data. Chalciporus rubrostipitatus is characterized by basidiomata having purplish red to reddish pileus with subtomentose to rugose surface, whitish pileal context, round to angular pores, and reddish orange to red stipe, which is pruinose toward the apex. Tylopilus purpureus produces basidiomata having a purple to vinaceous purple pileus, whitish pore surface that changes to reddish brown on bruising, and a minutely pubescent purplish stipe. Morphological descriptions and comparisons, taxonomic keys, and results of phylogenetic analyses using sequences of the ITS (internal transcribed spacer), 28S (28S rRNA), and RPB2 (second largest subunit of RNA polymerase II) gene regions are presented.

New Cortinariaceae species associated with Dicymbe, Aldina, and Pakaraimaea in Guyana.

Species of the ectomycorrhizal (ECM) family Cortinariaceae (Agaricales, Agaricomycetes, Basidiomycota) have long been considered impoverished or absent from lowland tropical rainforests. Several decades of collecting in forests dominated by ECM trees in South America's Guiana Shield is countering this view, with discovery of numerous Cortinariaceae species. To date, ~12 morphospecies of this family have been found in the central Pakaraima Mountains of Guyana. Here, we describe three of these as new species of Cortinarius and two as new species of Phlegmacium from forests dominated by the ECM tree genera Dicymbe (Fabaceae subfam. Detarioideae), Aldina (Fabaceae subfam. Papilionoideae), and Pakaraimaea (Cistaceae). Macromorphological, micromorphological, habitat, and DNA sequence data are provided for each new species.

Fossils can reveal a long-vanished combination of character states: Evidence from a mysterious foliicolous anamorphic fungus from the Middle Siwalik (Late Miocene) of Himachal Pradesh, India.

Fossils can unveil a long-vanished combination of character states that inform inferences about the timing and patterns of diversification of modern fungi. By examining the well-preserved stacked chained vesicular conidiophores developed in clusters from the basal stroma, we describe a new taxon of fossil Zygosporiaceae with a combination of characters unknown among extant taxa on compressed serrated-margined dicot leaf (cf. Fagaceae) recovered from the Siwalik sediments (Late Miocene; ca. 12-8 Ma) of Himachal Pradesh, western Himalaya. Based upon conidiophore morphology, our Siwalik fungal remains, similar to Zygosporium Mont. (Zygosporiaceae: Xylariales: Sordariomycetes), are recognized as a new fossil species, Z. stromaticum Kundu & Khan, sp. nov. Zygosporium stromaticum is the only known fossil anamorphic fungus that occurs on plant cuticles and has a cluster of stacked chained vesicular conidiophores arising from a poorly preserved basal stroma formed by irregular, thick-walled cells. Its combination of morphological characteristics is unknown in extant fungal taxa, so Z. stromaticum likely represents a new anamorphic foliicolous fungus that may now be extinct. This unique evidence may be essential for the calibration of divergence time estimations of fungal lineages.

Agaricus subgenus Pseudochitonia in Malakand, Pakistan: An updated phylogeny and description of three new species.

Agaricus is a genus with more than 500 species. Most of the new species reported since 2000 are tropical or subtropical. The study area, the Malakand region, located in the north of Pakistan, has a subtropical climate. In this study, nine species, including three new species, of Agaricus subgenus Pseudochitonia, are reported from this region. Description of the new species are based on morphological characteristics and phylogenetic analyses using three DNA regions: nuc ribosomal DNA internal transcribed spacers (ITS), fragments of the large subunit of nuc ribosomal DNA (28S), and the translation elongation factor 1-alpha gene (TEF1). One new species, Agaricus lanosus, with wooly squamules on its cap, forms a lineage within Agaricus sect. Bivelares and cannot be classified with certainty in one of the two subsections (Cupressorum and Hortenses) of this section. Agaricus rhizoideus with rhizoid-like structure at the base of the stipe forms a basal clade in Agaricus sect. Hondenses. Specimens of the third new species, Agaricus malakandensis, form a species-level clade within Agaricus sect. Catenulati and exhibits the morphological characteristics of this section. Due to their similar ITS sequences, two previously unnamed specimens from Thailand (A. sp. LD2012162 and CA799) are considered conspecific with A. malakandensis.

Three new species of Agaricus from Baiyun Mountain, Guangzhou, China.

Agaricus is a species-rich genus with more than 600 species around the world. In this work, three new species, Agaricus cacainus, A. baiyunensis, and A. praeclarefibrillosus are described from the specimens collected at Baiyun Mountain, Guangzhou, China, a subtropical area with a monsoon maritime climate, based on phylogenetic analyses and morphological examinations of internal transcribed spacer (ITS1-5.8S-ITS2 = ITS), D1/D2 domains of the large subunit of ribosomal DNA (28S), and a part of translation elongation factor 1-alpha (TEF1). Agaricus cacainus in A. sect. Amoeni is characterized by a parabolic to applanate, slightly depressed pileus covered with chocolate brown, appressed, triangular squamules against white background, a white, furfuraceous stipe, an unchanging context when cut, a fragile and evanescent annulus, usually 4- or 2-spored basidia, and mostly pyriform cheilocystidia. Agaricus baiyunensis in A. sect. Minores has a pileus with a slightly truncate top covered with light brown, downy-wooly fibrillose scales and a light yellowish stipe with membranous annulus. Agaricus praeclarefibrillosus in A. sect. Brunneopicti is characterized by a pileus surface with brownish, triangular, recurved scales and longitudinally splitting lines toward margin, a cottony stipe with white, tiny, recurved fibrils, a single annulus, and variously shaped cheilocystidia, with sparsely ornamented basidiospores. The detailed comparison of their morphological characteristics with closely related species is provided.

Geometric morphometric analysis of spore shapes improves identification of fungi.

Morphology of organisms is an essential source of evidence for taxonomic decisions and understanding of ecology and evolutionary history. The geometric structure (i.e., numeric description of shape) provides richer and mathematically different information about an organism's morphology than linear measurements. A little is known on how these two sources of morphological information (shape vs. size) contribute to the identification of organisms when implied simultaneously. This study hypothesized that combining geometric information on the outline with linear measurements results in better species identification than either evidence alone can provide. As a test system for our research, we used the microscopic spores of fungi from the genus Subulicystidium (Agaricomycetes, Basidiomycota). We analyzed 2D spore shape data via elliptic Fourier and principal component analyses. Using flexible discriminant analysis, we achieved the highest species identification success rate for a combination of shape and size descriptors (64.7%). The shape descriptors alone predicted species slightly better than size descriptors (61.5% vs. 59.1%). We conclude that adding geometric information on the outline to linear measurements improves the identification of the organisms. Despite the high relevance of spore traits for the taxonomy of fungi, they were previously rarely analyzed with the tools of geometric morphometrics. Therefore, we supplement our study with an open access protocol for digitizing and summarizing fungal spores' shape and size information. We propagate a broader use of geometric morphometric analysis for microscopic propagules of fungi and other organisms.

Discovery of Fungus-Specific Targets and Inhibitors Using Chemical Phenotyping of Pathogenic Spore Germination.

There is a critical need for new antifungal drugs; however, the lack of available fungus-specific targets is a major hurdle in the development of antifungal therapeutics. Spore germination is a differentiation process absent in humans that could harbor uncharacterized fungus-specific targets. To capitalize on this possibility, we developed novel phenotypic assays to identify and characterize inhibitors of spore germination of the human fungal pathogen Cryptococcus. Using these assays, we carried out a high-throughput screen of ∼75,000 drug-like small molecules and identified and characterized 191 novel inhibitors of spore germination, many of which also inhibited yeast replication and demonstrated low cytotoxicity against mammalian cells. Using an automated, microscopy-based, quantitative germination assay (QGA), we discovered that germinating spore populations can exhibit unique phenotypes in response to chemical inhibitors. Through the characterization of these spore population dynamics in the presence of the newly identified inhibitors, we classified 6 distinct phenotypes based on differences in germination synchronicity, germination rates, and overall population behavior. Similar chemical phenotypes were induced by inhibitors that targeted the same cellular function or had shared substructures. Leveraging these features, we used QGAs to identify outliers among compounds that fell into similar structural groups and thus refined relevant structural moieties, facilitating target identification. This approach led to the identification of complex II of the electron transport chain as the putative target of a promising structural cluster of germination inhibitory compounds. These inhibitors showed high potency against Cryptococcus spore germination while maintaining low cytotoxicity against mammalian cells, making them prime candidates for development into novel antifungal therapeutics. IMPORTANCE Fungal pathogens cause 1.5 million deaths annually, and there is a critical need for new antifungal drugs. However, humans and fungi are very similar on a molecular level, and so many drugs that kill fungi also damage human cells, leading to extreme side effects, including death. The lack of fungus-specific targets is a major hurdle in the development of antifungal therapeutics. Spore germination is a process absent in humans that could harbor fungus-specific targets. To capitalize on this possibility, we developed new assays to identify and characterize inhibitors of spore germination of the human fungal pathogen Cryptococcus. Using these assays, we identified and characterized 191 novel inhibitors of spore germination. These inhibitors showed high potency against Cryptococcus spore germination while maintaining low cytotoxicity against mammalian cells, making them prime candidates for development into novel antifungal therapeutics.

Can wood-decaying urban macrofungi be identified by using fuzzy interference system? An example in Central European Ganoderma species.

Ganoderma is a cosmopolitan genus of wood-decaying basidiomycetous macrofungi that can rot the roots and/or lower trunk. Among the standing trees, their presence often indicates that a hazard assessment may be necessary. These bracket fungi are commonly known for the crust-like upper surfaces of their basidiocarps and formation of white rot. Six species occur in central European urban habitats. Several of them, such as Ganoderma adspersum, G. applanatum, G. resinaceum and G. pfeifferi, are most hazardous fungi causing extensive horizontal stem decay in urban trees. Therefore, their early identification is crucial for correct management of trees. In this paper, a fast technique is tested for the determination of phytopathologically important urban macrofungi using fuzzy interference system of Sugeno type based on 13 selected traits of 72 basidiocarps of six Ganoderma species and compared to the ITS sequence based determination. Basidiocarps features were processed for the following situations: At first, the FIS of Sugeno 2 type (without basidiospore sizes) was used and 57 Ganoderma basidiocarps (79.17%) were correctly determined. Determination success increased to 96.61% after selecting basidiocarps with critical values (15 basidiocarps). These undeterminable basidiocarps must be analyzed by molecular methods. In a case, that basidiospore sizes of some basidiocarps were known, a combination of Sugeno 1 (31 basidiocarps with known basidiospore size) and Sugeno 2 (41 basidiocarps with unknown basidiospore size) was used. 84.72% of Ganoderma basidiocarps were correctly identified. Determination success increased to 96.83% after selecting basidiocarps with critical values (11 basidiocarps).

Development of a loop-mediated isothermal amplification assay for the detection of Tilletia controversa based on genome comparison.

Tilletia controversa causing dwarf bunt of wheat is a quarantine pathogen in several countries. Therefore, its specific detection is of great phytosanitary importance. Genomic regions routinely used for phylogenetic inferences lack suitable polymorphisms for the development of species-specific markers. We therefore compared 21 genomes of six Tilletia species to identify DNA regions that were unique and conserved in all T. controversa isolates and had no or limited homology to other Tilletia species. A loop-mediated isothermal amplification (LAMP) assay for T. controversa was developed based on one of these DNA regions. The specificity of the assay was verified using 223 fungal samples comprising 43 fungal species including 11 Tilletia species, in particular 39 specimens of T. controversa, 92 of T. caries and 40 of T. laevis, respectively. The assay specifically amplified genomic DNA of T. controversa from pure cultures and teliospores. Only Tilletia trabutii generated false positive signals. The detection limit of the LAMP assay was 5 pg of genomic DNA per reaction. A test performance study that included five laboratories in Germany resulted in 100% sensitivity and 97.7% specificity of the assay. Genomic regions, specific to common bunt (Tilletia caries and Tilletia laevis together) are also provided.

Propagation and characterization of viable arbuscular mycorrhizal fungal spores within maize plant (Zea mays L.).

BACKGROUND: The harmful effect of chemical fertilizer application on human health and the environment as a modern method of meeting the food demand of the increasing world population demands an urgent alternative that is environmentally friendly, which will pose no harm to human health and the environment. Arbuscular mycorrhizal fungi (AMF) are beneficial soil microorganisms that provide various ecological functions in increasing soil fertility and enhancing plant growth. This present study aimed to propagate, characterize and examine the effect of viable arbuscular mycorrhizal fungal spores on maize (Zea mays L) hosts using molecular methods. The propagation of AMF in the host plant using sterile soil and vermiculite was conducted in the greenhouse. RESULT: The effect of AMF inoculation revealed a significant difference (P > 0.05) in maize growth, root colonization and AMF spore count when compared with the control. In all the parameters measured in this study, all the AMF spores propagated had a positive effect on the maize plant over the control, with the highest value mostly recorded in Rhizophagus irregularis AOB1. The molecular characterization of the spore using a specific universal primer for Glomeromycota established the success of the propagation process, which enhanced the classification of the AMF species into Rhizophagus irregularis OAB1, Glomus mosseae OAB2 and Paraglomus occultum OAB3. CONCLUSION: This finding will be a starting point in producing arbuscular mycorrhizal inoculum as a biofertilizer to enhance plant growth promotion. © 2021 Society of Chemical Industry.

Four new species of Talaromyces section Talaromyces discovered in China.

Four new Talaromyces species without any close relatives are reported here, namely, T. aureolinus (ex-type AS3.15865 T), T. bannicus (ex-type AS3.15862 T), T. penicillioides (ex-type AS3.15822 T), and T. sparsus (ex-type AS3.16003 T). Morphologically, T. aureolinus is unique in producing orange-yellow mycelium and gymnothecia, singly borne asci, and ellipsoidal, spiny ascospores. Talaromyces bannicus is characterized by the slow growth rate, polymorphic conidiophores, inconsistent stipe lengths, and pyriform to ellipsoidal, echinulate conidia. Talaromyces penicillioides is distinguished by good growth and sporulation on malt extract agar (MEA) and yeast extract sucrose agar (YES) media, resembling the colony appearances of certain Penicillium species, and appressed biverticillate and occasionally monoverticillate penicilli bearing globose to ellipsoidal, echinulate conidia. Talaromyces sparsus has wide, submerged colony margins with sparse aerial mycelium, and conidial areas overlaid with yellow-green, sterile hyphae on MEA medium. These four new species are well supported by individual phylogenetic trees based on ß-tubulin (BENA), calmodulin (CALM), DNA-dependent RNA polymerase II second largest subunit (RPB2), and internal transcribed spacer region (ITS) gene sequences and the tree of the concatenated BENA-CALM-RPB2 sequence.

Two new species and one new record of Xenosporium with ellipsoidal or ovoid conidia from Taiwan.

Three species of Xenosporium producing ellipsoidal or ovoid conidia were collected from decaying culms of Miscanthus floridulus submerged in freshwater streams of Alishan area, Chiayi County, Taiwan. Xenosporium formosiforme and X. parvulum are described and illustrated as new species. Xenosporium africanum is described in this paper as a new record for Taiwan. The phylogenetic relationships of Xenosporium species and related taxa were sought by comparing the sequences of their internal transcribed spacer (ITS) barcode, 28S rDNA, and RNA polymerase II second largest subunit (RPB2) gene segments. Phylogenetic analysis of these Xenosporium species supports their placement in the Tubeufiaceae. A synopsis of Xenosporium species producing ellipsoidal or ovoid conidia is given. The criteria used to differentiate species are discussed.

Four new species of Agaricus subgenus Spissicaules from China.

Agaricus subgenus Spissicaules is widely distributed in the world. In this study, 114 specimens were included in multigene phylogenetic analyses that allowed a better circumscription of the four sections in A. subg. Spissicaules. Three new species from China, A. brunneovariabilis, A. beijingensis, and A. planiceps, are described and placed in different sections. The invalidly described A. catenariocystidiosus is validated here as an additional new species. Comparisons between the sequences of the three closely related species A. thiersii, A. parasubrutilescens, and A. linzhiensis support the distinction between these three species despite the paraphyly of A. linzhiensis, which results from its high intraspecific variability with numerous heteromorphisms.

Morphological and genetic characteristics of the novel entomopathogenic fungus Ophiocordyceps langbianensis (Ophiocordycipitaceae, Hypocreales) from Lang Biang Biosphere Reserve, Vietnam.

An entomopathogenic fungus newly named Ophiocordyceps langbianensis was collected from Lang Biang Biosphere Reserve, located in Lam Dong Province, Vietnam. It is characterized as a species of Ophiocordyceps (Ophiocordycipitaceae, Hypocreales) having the unique characteristics of a cylindrical fertile part and several branched apical appendices. Each ascospore develops as two swollen, constricted part-spores. A phylogenetic analysis of multiple genes, including nrLSU, nrSSU, Rpb1, ITS and Tef, supported its systematic position in the genus of Ophiocordyceps; it is related to O. brunneipunctata. Based on morphological and phylogenetic analyses, O. langbianensis was confirmed as a new species from Vietnam.

Steccherinum tenuissimum and S. xanthum spp. nov. (Polyporales, Basidiomycota): New species from China.

Two new wood-inhabiting fungal species, Steccherinum tenuissimum and S. xanthum spp. nov. are described based on a combination of morphological features and molecular evidence. Steccherinum tenuissimum is characterized by an annual growth habit, resupinate basidiomata with an odontioid hymenial surface, a dimitic hyphal system with clamped generative hyphae, strongly encrusted cystidia and basidiospores measuring 3-5 × 2-3.5 µm. Steccherinum xanthum is characterized by odontioid basidiomata and a monomitic hyphal system with generative hyphae bearing clamp connections and covering by crystals, colourless, thin-walled, smooth, IKI-, CB-and has basidiospores measuring 2.7-5.5 × 1.8-4.0 µm. Sequences of the ITS and nLSU nrRNA gene regions of the studied samples were generated, and phylogenetic analyses were performed with maximum likelihood, maximum parsimony and Bayesian inference methods. The phylogenetic analyses based on molecular data of ITS + nLSU sequences showed that two new Steccherinum species felled into the residual polyporoid clade. Further investigation was obtained for more representative taxa in Steccherinum based on ITS + nLSU sequences, which demonstrated that S. tenuissimum and S. xanthum were sister to S. robustius with high support (100% BP, 100% BS and 1.00 BPP).

Atypical chlamydoconidium-producing Trichophyton tonsurans strains from Ceará State, Northeast Brazil: investigation of taxonomy by phylogenetic analysis and biofilm susceptibility.

Chlamydoconidium-producing Trichophyton tonsurans strains isolated in Northeastern Brazil have morphological features different from the classic description of this dermatophyte species. This study investigated the phylogenetic relationship of chlamydoconidium-producing T. tonsurans strains isolated in Northeastern Brazil. Also, the effect of terbinafine and farnesol on mature biofilms of T. tonsurans strains was evaluated. The mass spectra of T. tonsurans strains were investigated by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The ITS and LSU loci regions of rDNA and the partial ß-tubulin gene were sequenced and the phylogenetic tree was analysed. The effects of terbinafine and farnesol on mature T. tonsurans biofilms were evaluated through the analysis of metabolic activity, quantification of biomass and observation by scanning electron microscopy. MALDI-TOF MS spectra of the chlamydoconidium-producing T. tonsurans strains differed from the spectrum of the control strain (ATCC 28942), presenting an intense ion peak at m/z 4155 Da. Phylogenetic tree analysis showed that the chlamydoconidium-producing strains isolated in Northeastern Brazil are allocated to a single cluster, differing from strains isolated from other countries. As for mature T. tonsurans biofilms, farnesol reduced biomass and metabolic activity by 64.4 and 65.9 %, respectively, while terbinafine reduced the biomass by 66.5 % and the metabolic activity by 69 %. Atypical morphological characteristics presented by chlamydoconidium-producing T. tonsurans strains result from phenotypic plasticity, possibly for adaptation to environmental stressors. Also, farnesol had inhibitory activity against T. tonsurans biofilms, demonstrating this substance can be explored for development of promising anti-biofilm drugs against dermatophytes.