Spore Septation Research Articles

Morphological and genetic characterization of Fusarium oxysporum and its management using weed extracts in cotton

Fusarium oxysporum, a fungal plant pathogen, causes severe wilting and heavy losses in cotton. Present research was planned to appraise the weed extracts of Parthenium hysterophorus, Chenopodium album, Canada thistle and Phalaris minor against F. oxysporum. Morphological identification of F. oxysporum was done by observing white cottony mycelium with dark-purple undersurface on growth media and oval to ellipsoid/kidney shaped oval tapering and three septate spores. Molecular characterization was done by amplifying internal transcribed spacer region using the ITS universal primers, ITS1 and ITS4. The weed extract with concentrations of 5%, 10%, 15% and 20% were applied by using food poison techniques under complete randomized design. Data was taken 3, 5 and 7 days after inoculation of F. oxysporum on potato dextrose agar (PDA). P. hysterophorus showed maximum antifungal response (97%) against F. oxysporum whereas other treatments effectively inhibited the pathogen growth on PDA media. Tebuconazole, a fungicide, was used as positive control. Trichoderma harzianum showed 98% inhibition of F. oxysporum on PDA. Consortium of Trichoderma harzianum + weed extracts was applied in infected roots of cotton grown in pots under complete randomized design. No disease was observed in treatment P. hysterophorus + T. harzianum whereas maximum disease was calculated (50%) in other treatments as compared to control (100%).

Morphological and Molecular Identification of the Causal Agent of Anthracnose Disease of Avocado in Kenya.

Anthracnose disease of avocado contributes to a huge loss of avocado fruits due to postharvest rot in Kenya. The causal agent of this disease has not been clear but presumed to be Colletotrichum gloeosporioides as reported in other regions where avocado is grown. The fungus mainly infects fruits causing symptoms such as small blackish spots, “pepper spots,” and black spots with raised margin which coalesce as infection progresses. Due to economic losses associated with the disease and emerging information of other species of fungi as causal agents of the disease, this study was aimed at identifying causal agent(s) of the disease. A total of 80 fungal isolates were collected from diseased avocado fruits in Murang'a County, the main avocado growing region in Kenya. Forty-six isolates were morphologically identified as Colletotrichum spp. based on their cultural characteristics, mainly whitish, greyish, and creamish colour and cottony/velvety mycelia on the top side of the culture and greyish cream with concentric zonation on the reverse side. Their spores were straight with rounded end and nonseptate. Thirty-four isolates were identified as Pestalotiopsis spp. based on their cultural characteristics: whitish grey mycelium with black fruiting structure on the upper side and greyish black one on the lower side and septate spores with 3-4 septa and 2 or 3 appendages at one end. Further molecular studies using ITS indicated Colletotrichum gloeosporioides, Colletotrichum boninense, and Pestalotiopsis microspora as the causal agents of anthracnose disease in avocado. However, with this being the first report, there is a need to conduct further studies to establish whether there is coinfection or any interaction thereof.

Una especie nueva y peculiar de Graphis (Ascomycota: Ostropales: Graphidaceae) de la selva alta perennifolia de Los Tuxtlas, Veracruz, México

Graphis robertusii (G. robertusii) Bárcenas-Peña, Herrera-Campos and Miranda is described for the first time from the tropical rain forest in Los Tuxtlas, Veracruz. It is a conspicuous species characterized by erumpent lirella with lateral thalline margin separated from the excipulum, labia entire and white pruinose, completely carbonized excipulum, inspersed hymenium, transversally septate spores, and stictic, salazinic and constictic acids as secondary metabolites. G. robertusii was found on cortex at the canopy of several sites within Los Tuxtlas Biosphere Reserve, Veracruz and it is one of the most abundant corticolous crustose lichen species in the region.

First report of Fusarium wilt of eggplant caused by Fusarium oxysporum f. sp. melongenae in Iran

In 2012, eggplant (Solanum melongena) production in several greenhouses and fields was surveyed in Iran. In Hormozgan and Semnan provinces, 15 and 12% of fields surveyed, respectively, were infected with an unknown disease. Those affected plants exhibited leaf chlorosis and slight vein clearing on the outer leaflets, slight yellowing of foliage and wilting of upper leaves and eventual death of the plant. Necrotic tissue fragments from discoloured vascular stem tissue were surface sterilised by soaking in 10% bleach solution for five minutes and plated on potato dextrose agar (PDA). Single-spore isolates were obtained and transferred to PDA and carnation leaf agar (CLA) to investigate culture characteristics and morphology (Nelson et al., 4). Twenty-six isolates were identified as Fusarium., including 12 isolates that were initially identified as Fusarium oxysporum due to production of characteristic three to five septate, sickle-shaped macroconidia with a foot-shaped basal cell, on branched conidiophores or on the surface of sporodochia. Three septate spores were more common. Microconidia were borne on simple phialides arising laterally and were abundant, oval-ellipsoid, straight to curved and non-septate in culture. A typical cream to pink colony developed, often with purple tinge, on PDA (Nelson et al., 4). After PCR amplification of genomic DNA using the specific primer PF02-3 (Baysal et al., 1), morphological identity was confirmed as Fusarium oxysporum f. sp. melongenae by the presence of a specific, characteristic band visible at around 70 bp. The other isolates were identified as F. solani. Pathogenicity tests were performed twice for each of 12 isolates using a root-dip inoculation method (Baysal et al., 1). Wounded roots ofnine S. melongena (cv. ‘Pala‘) seedlings at the six-leaf stage were submerged for 15 min in a conidial suspension (1 times 106 conidia/ml in sterile water), while control plants were dipped in sterile tap water. Seedlings were transplanted into pots and maintained in a growth chamber. After 3-4 weeks, severity of wilt symptoms was assessed using a wilt index ranging from 0 (no symptoms) to 4 (plant death) (Morid et al., 3). All 12 isolates tested were pathogenic to eggplant with a wilt index ranging from 1.2 to 3.4 (average = 2.8). Symptoms observed on inoculated plants were similar to those in commercial greenhouses, including leaf chlorosis and necrosis and eventual death. Control plants showed no symptoms, and two other members of the Solanaceae (tomato and pepper) tested with the same method displayed no symptoms. Fusarium oxysporum f. sp. melongenae was successfully re-isolated from the stems of disease-affected inoculated plants, thereby completing Koch's postulates. Fusarium oxysporum f. sp. melongenae is a major soil-borne pathogen and one of the causal agents of vascular wilt disease in eggplant. Occurrence of F. oxysporum on S. melongena has been reported in Japan, Korea, China, Italy, Greece, Spain, Turkey, the USSR, USA-Florida and Fiji (Yildiz et al., 5). This is the first report of F. oxysporum f. sp. melongenae in Iran. Previously, the causal agent of Fusarium wilt of eggplant in Iran was attributed solely to F. solani (Gerlach & Ershad, 2).

Two new species of the lichen genus Phlyctis in India

Phlyctis subagelaea, with muriform spores and P. karnatakana with septate spores are newly described from India. Both species have a restricted distribution in Western Ghats south India where they grow on tree trunks in evergreen forest.

CmdABCDEF, a cluster of genes encoding membrane proteins for differentiation and antibiotic production in Streptomyces coelicolorA3(2)

BackgroundStreptomyces coelicolor is the most studied Streptomyces species and an excellent model for studying differentiation and antibiotic production. To date, many genes have been identified to be required for its differentiation (e.g. bld genes for aerial growth and whi genes for sporulation) and antibiotics production (including actII-orf4, redD, cdaR as pathway-specific regulatory genes and afsR, absA1/A2 as pleiotropic regulatory genes).ResultsA gene cluster containing six genes (SCO4126-4131) was proved to be co-transcribed in S. coelicolor. Deletions of cmdABCDEF (SCO4126-4131) displayed defective sporulation including formation of aberrant branches, and abnormalities in chromosome segregation and spore septation. Disruption mutants of apparently orthologous genes of S. lividans and S. avermitilis also showed defective sporulation, implying that the role of these genes is similar among Streptomyces. Transcription of cmdB, and therefore presumably of the whole operon, was regulated developmentally. Five of the encoded proteins (CmdA, C, D, E, F) were predicted membrane proteins. The other, CmdB, a predicted ATP/GTP-binding protein with an ABC-transporter-ATPase domain shown here to be essential for its function, was also located on the cell membrane. These results indicate that CmdABCDEF proteins mainly affect Streptomyces differentiation at an early stage of aerial hyphae formation, and suggest that these proteins may form a complex on cell membrane for proper segregation of chromosomes. In addition, deletions of cmdABCDEF also revealed over-production of blue-pigmented actinorhodin (Act) via activation of transcription of the pathway-specific regulatory gene actII-orf4 of actinorhodin biosynthesis.ConclusionIn this study, six co-transcribed genes cmdABCDEF were identified by their effects on differentiation and antibiotic production in Streptomyces coelicolor A3(2). These six membrane-located proteins are possibly assembled into a complex to function.

On the evolution of the Hysteriaceae and Mytilinidiaceae ( Pleosporomycetidae, Dothideomycetes, Ascomycota) using four nuclear genes

We present a molecular phylogenetic analysis for two families within the Pleosporomycetidae ( Dothideomycetes), the Hysteriaceae, and the Mytilinidiaceae, using four nuclear genes, the ribosomal LSU and SSU, transcription elongation factor 1 α and the second largest RNA polymerase II subunit. Multigene phylogenies provide strong support for the monophyly of the Hysteriaceae and of the Mytilinidiaceae, both within the Pleosporomycetidae. However, sequence data also indicate that both families are not closely related within the subclass. Although core groups for many of the genera in the Hysteriaceae have been defined, Hysterium, Gloniopsis, and Hysterographium are polyphyletic, with affinities not premised on spore septation and pigmentation. Glonium is also polyphyletic, but along two highly divergent lines. The genus lies outside of the Hysteriaceae, and finds close affinities instead with the family Mytilinidiaceae, for which we propose Gloniaceae fam. nov. to accommodate the type, G. stellatum and related forms. The genus Psiloglonium is reinstated within the Hysteriaceae, with P. lineare, as type, to accommodate non-subiculate species, with apically obtuse didymospores. Farlowiella is removed from the Hysteriaceae, but remains within the Pleosporomycetidae. In contrast, despite divergent spore morphologies, the genera Mytilinidion and Lophium form a strongly supported clade, thus defining a highly monophyletic Mytilinidiaceae, adjacent to the Gloniaceae, for which we propose the Mytilinidiales ord. nov. The genus Ostreichnion, previously in the Mytilinidiaceae, is here transferred to the Hysteriaceae. It is concluded that the evolution of the hysterothecium occurred multiple times within the Pleosporomycetidae, and alone it is not a synapomorphic character state for the Hysteriaceae.

A molecular phylogenetic reappraisal of the Hysteriaceae, Mytilinidiaceae and Gloniaceae (Pleosporomycetidae, Dothideomycetes) with keys to world species

A reappraisal of the phylogenetic integrity of bitunicate ascomycete fungi belonging to or previously affiliated with the Hysteriaceae, Mytilinidiaceae, Gloniaceae and Patellariaceae is presented, based on an analysis of 121 isolates and four nuclear genes, the ribosomal large and small subunits, transcription elongation factor 1 and the second largest RNA polymerase II subunit. A geographically diverse and high density taxon sampling strategy was employed, including multiple isolates/species from the following genera: Anteaglonium (6/4), Encephalographa (1/1), Farlowiella (3/1), Gloniopsis (8/4), Glonium (4/2), Hysterium (12/5), Hysterobrevium (14/3), Hysterographium (2/1), Hysteropatella (2/2), Lophium (4/2), Mytilinidion (13/10), Oedohysterium (5/3), Ostreichnion (2/2), Patellaria (1/1), Psiloglonium (11/3), Quasiconcha (1/1), Rhytidhysteron (8/3), and 24 outgroup taxa. Sequence data indicate that although the Hysteriales are closely related to the Pleosporales, sufficient branch support exists for their separation into separate orders within the Pleosporomycetidae. The Mytilinidiales are more distantly related within the subclass and show a close association with the Gloniaceae. Although there are examples of concordance between morphological and molecular data, these are few. Molecular data instead support the premise of a large number of convergent evolutionary lineages, which do not correspond to previously held assumptions of synapomorphy relating to spore morphology. Thus, within the Hysteriaceae, the genera Gloniopsis, Glonium, Hysterium and Hysterographium are highly polyphyletic. This necessitated the transfer of two species of Hysterium to Oedohysterium gen. nov. (Od. insidens comb. nov. and Od. sinense comb. nov.), the description of a new species, Hysterium barrianum sp. nov., and the transfer of two species of Gloniopsis to Hysterobrevium gen. nov. (Hb. smilacis comb. nov. and Hb. constrictum comb. nov.). While Hysterographium, with the type Hg. fraxini, is removed from the Hysteriaceae, some of its species remain within the family, transferred here to Oedohysterium (Od. pulchrum comb. nov.), Hysterobrevium (Hb. mori comb. nov.) and Gloniopsis (Gp. subrugosa comb. nov.); the latter genus, in addition to the type, Gp. praelonga, with two new species, Gp. arciformis sp. nov. and Gp. kenyensis sp. nov. The genus Glonium is now divided into Anteaglonium (Pleosporales), Glonium (Gloniaceae), and Psiloglonium (Hysteriaceae). The hysterothecium has evolved convergently no less than five times within the Pleosporomycetidae (e.g., Anteaglonium, Farlowiella, Glonium, Hysterographium and the Hysteriaceae). Similarly, thin-walled mytilinidioid (e.g., Ostreichnion) and patellarioid (e.g., Rhytidhysteron) genera, previously in the Mytilinidiaceae and Patellariaceae, respectively, transferred here to the Hysteriaceae, have also evolved at least twice within the subclass. As such, character states traditionally considered to represent synapomorphies among these fungi, whether they relate to spore septation or the ascomata, in fact, represent symplesiomorphies, and most likely have arisen multiple times through convergent evolutionary processes in response to common selective pressures.

Enterographa Oregonensis (Roccellaceae), a New Foliicolous Species from The Northwest Coast of North America

A new foliicolous lichen species, Enterographa oregonensis (Ascomycota: Arthoniales: Roccellaceae) is described from temperate coastal North America. It differs from similar, tropical species in its combination of 5(-7)-septate spores, a gelatinous perispore, short lirellae and presence of gyrophoric acid. The ecology of this species is discussed and a conservation assessment is recommended.

Molecular phylogeny and systematics of Polyblastia ( Verrucariaceae, Eurotiomycetes) and allied genera

Phylogenetic relationships of the lichen genus Polyblastia and closely related taxa in the family Verrucariaceae ( Verrucariales, Chaetothyriomycetidae) were studied. A total of 130 sets of sequences (nuLSU rDNA, nuITS rDNA and RPB1 region A–D), including 129 newly generated sequences, were analysed. Phylogenetic relationships were inferred using a Bayesian approach based on two datasets. A first analysis of a larger, two-locus dataset (nuLSU and RPB1) for 128 members of the Verrucariaceae, confirmed the polyphyly of Polyblastia, Thelidium, Staurothele, and Verrucaria, as currently construed. The second analysis focused on 56 Polyblastia and allied taxa, but using an additional locus (nuITS rDNA) and two closely related outgroup taxa. The latter analysis revealed strongly supported groups, such as Polyblastia s. str., the Thelidium group (a mixture of Polyblastia, Thelidium, Staurothele and Verrucaria species). The genus Sporodictyon, which is here accepted, also accommodates Sporodictyon terrestre comb. nov. Morphological features traditionally used for characterizing Polyblastia, Thelidium, Staurothele and Verrucaria, such as spore septation and colour, occurrence of hymenial photobiont, involucrellum structure, and substrate preference, were found to be only partially consistent within the strongly supported clades, and thus are not always reliable features for characterizing natural groups.

Structurally preserved ascomycetous fungi from the Maastrichtian type area (NE Belgium)

Various structurally preserved ascomycetous fungus structures found in and on leaves of the Late Maastrichtian conifer Brachyphyllum patens (Cheirolepidiaceae?) are described: (1) stomatal hypostromata with attached hyphae and a probable fruit body ( Pteropus brachyphylli, gen. et sp. nov., Venturiaceae); (2) nonstomatal epicuticular stromata, including a thyriothecium with septate spores (?Micropeltidaceae, ?Microthyriaceae); (3) nonstomatal subcuticular stromata (?Phacidiaceae, ?Rhytismataceae); and (4) unidentified epicuticular and endophytical hyphae. Pteropus brachyphylli is considered as a close relative of extant Phaeocryptopus (Venturiaceae), species of which infect leaves of conifers belonging to the Araucariaceae, Cupressaceae, Pinaceae and Podocarpaceae. Pteropus brachyphylli may have been closely associated with cheirolepidiaceous conifers, which became extinct near the end of the Cretaceous. To date, it is the only fossil representative of Phaeocryptopus-like fungi. Pteropus brachyphylli is believed to have occupied a niche comparable to that of its modern relatives, which are weak parasites or sometimes saprophytes. Its presence in the Late Maastrichtian sets a minimum age of c. 66.5 million years for the kind of host–fungus relationships as nowadays present between conifers and Phaeocryptopus species.

Chaenothecopsis in a molecular phylogeny based on nuclear rDNA ITS and LSU sequences

AbstractBayesian inference analyses of nuclear LSU rDNA sequences showed Verrucariales and Eurotiales to form the sistergroup of Mycocaliciales. A more detailed analysis of ITS rDNA sequences showed Sphinctrinaceae to be embedded in Mycocaliciaceae. Mycocaliciales contain two major lineages. Intron occurrence and phylogeny was partly congruent with the ITS‐based phylogeny. Chaenothecopsis is paraphyletic with respect to Phaeocalicium, Mycocalicium, Sphinctrina and Stenocybe. Some morphological features traditionally used for characterising Chaenothecopsis and other genera in Mycocaliciales, such as ascus apex structure and stalk anatomy, were found to be homoplasious, while others, such as spore septation, intron distribution and nutritional biology, were consistent with major clades in the analysis. Within the two major clades of Mycocaliciales some subclades are strongly supported and well characterized by anatomical, nutritional and intron features.

Outline of phylogeny and character evolution in Rhizocarpon (Rhizocarpaceae, lichenized Ascomycota) based on nuclear ITS and mitochondrial SSU ribosomal DNA sequences

The phylogeny of the lichen genus Rhizocarpon (Rhizocarpaceae, lichenized Ascomycota) was investigated using nucleotide sequences from the ITS region of the nuclear ribosomal DNA and the SSU region of the mitochondrial ribosomal DNA from 13 species of Rhizocarpon, Catolechia wahlenbergii and Poeltinula cerebrina. Phylogenetic estimations were performed using maximum parsimony and Bayesian MCMC tree sampling. Twelve phylogenetic null hypotheses were tested using MCMC tree sampling. The evolution of five morphological characters was assessed by mapping them onto MCMC tree samples. The results indicate that Rhizocarpon in its current sense is polyphyletic and can only be made monophyletic if R. hochstetteri is excluded or Poeltinula, and possibly also Catolechia, are included. The root placement in the Rhizocarpaceae is ambiguous, either Catolechia or Poeltinula + R. hochstetteri being the sistergroup to the rest of the family. Previously suggested infrageneric arrangements based on presence or absence of the yellow substance rhizocarpic acid in the thallus or the septation of the ascospores are unnatural. Some species with grey or brown thallus may have evolved from a yellow ancestor. Spore septation and colour, amyloidity of the thalline medulla, and the presence of stictic acid complex and rhizocarpic acid are shown to have changed multiple times during the course of evolution. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society, 2002, 77, 535–546.

Systematics of Paraphaeosphaeria: a molecular and morphological approach

The genus Paraphaeosphaeria (Loculoascomycetes) was described as a segregate of Leptosphaeria for species producing brown, usually punctate ascospores with rounded ends, a submedian primary septum, an inflated cell above the primary septum, and a Coniothyrium sensu lato anamorph. This study evaluated the taxonomic value of the morphological characters, host range, ecology, and anamorphs in relation to DNA sequence data in order to determine the relationship between species described in Paraphaeosphaeria. Nine species were characterized morphologically and the ITS and 18S regions of the rDNA were sequenced and a phylogeny was inferred. Morphological studies and results of the sequence analyses provide strong support for polyphyly of this genus. Based on these analyses, the concept of Paraphaeosphaeria should be narrowed to reflect a monophyletic generic concept. Characters such as spore septation and method of conidiogenesis were found to predict relatedness.

Evolutionary trends in the Physciaceae

Abstract:The current delimitation of the family Physciaceae has been generally accepted since detailed descriptions of ascus characters allowed for a more natural circumscription of lichenized ascomycetes. The generic relations within the family are, however, still controversial and depend on the importance different authors attribute to specific morphological or chemical characteristics. The aim of this paper is to describe ascospore ontogeny and to test the present taxonomic structure of the family against a parsimony-based cladistic analysis, which includes three different scenarios of a priori character weighting. A study of ascospore ontogeny revealed two distinct developmental lines. One line revealed a delayed septum formation, which clearly showed transitions from spores with apical and median thickenings to spores without apical, but still well developed median thickenings, and to spores without any thickenings. In the second developmental line with an early septum formation, again taxa with no thickenings, median thickenings, and both median and apical thickenings were found. Although these characters were constant at a species level, median wall thickenings especially varied among otherwise closely related taxa. In the cladistic analyses the current taxonomic structure of the Physciaceae was only obtained after the five character groups, namely morphology and anatomy of the vegetative thallus, conidiomata and conidia, morphology and anatomy of the apothecia, ontogeny of the ascospores, and secondary metabolites of the thallus, were given equal importance, and after a subjective a priori weighting further increased the weight of the three characters ‘conidial shape’, ‘presence of apical thickenings’, and ‘spore septation delayed’. This structure was not supported by a cladistic analysis with equally weighted characters but reflected the biased character weighting of the present day Physciaceae taxonomy. The taxonomic importance of conidial characters and of anatomical and ontogenetical spore characteristics need, therefore, a careful reconsideration in future.

Waynea hirsuta, a new epiphytic lichen species from Central Siberia

A new lichen, Waynea hirsuta is described from the Tunkinsky range, Lake Bajkal region, Central Siberia. It has a squamulose, sorediate thallus, (0‐) 1 (‐3) septate spores, labriform soralia, and positive reactions to K and to N of epithecium, excipulum and upper cortex. The thalline squamules have a dense cover of hyaline hairs. The material was collected on the bark of old Populus balsamifera trees in a close stand of Pinus sibirica. The affinities with the other three species of the genus, and with some Hypocenomyce species are discussed.

Ascospore septation inDiploschistes (Thelotremataceae, lichenizedAscomycota) and the taxonomic significance of macro- and microcephalic ascospore types

The ascospore septation in 13 species ofDiploschistes was examined. Microcephalic, macrocephalic, as well as irregular ascospore septation were found. In some species and even specimens of some species, different types of spore septation were detected. The taxonomic significance of the character of ascospore septation sequence is questioned, and the distinction of the ordersGraphidales andOstropales, which was primarily based on this character, is rejected.

Characterization of cell cycle events during the onset of sporulation in Bacillus subtilis

To elucidate the process of asymmetric division during sporulation of Bacillus subtilis, we have measured changes in cell cycle parameters during the transition from vegetative growth to sporulation. Because the propensity of B. subtilis to grow in chains of cells precludes the use of automated cell-scanning devices, we have developed a fluorescence microscopic method for analyzing cell cycle parameters in individual cells. From the results obtained, and measurements of DNA replication fork elongation rates and the escape time of sporulation from the inhibition of DNA replication, we have derived a detailed time scale for the early morphological events of sporulation which is mainly consistent with the cell cycle changes expected following nutritional downshift. The previously postulated sensitive stage in the DNA replication cycle, beyond which the cell is unable to sporulate without a new cell cycle, could represent a point in the division cycle at which the starved cell cannot avoid attaining the initiation mass for DNA replication and thus embarking on another round of the cell cycle. The final cell cycle event, formation of the asymmetric spore septum, occurs at about the time in the cell cycle at which the uninduced cell would have divided centrally, in keeping with the view that spore septation is a modified version of vegetative division.

New species of Roccellinastrum with an emendation of the genus

The genus Roccellinastrum Follm. emend. Henssen & Vobis is placed in the Lecideaceae. Two new species are described, R. epiphyllum Henssen & Vobis, from Chile and R. neglectum Henssen & Vobis, from New Zealand and Tasmania. The new combination R. candidum (Mull. Arg.) Henssen is proposed. Roccellinastrum is characterized by apothecia of diverse shape without a proper margin, and a developmental morphology corresponding to that of the Lecanorales, by small amyloid asci, branched paraphyses and excipular hyphae, a byssoid–spon–giose thallus composed of thick–walled hyphae, and members of the Chlorococcales as phycobionts. The principal chemical constituent is protocetraric acid. The species have different spore septation and chemistry. Summary in Spanish.

The Corticolous Species of Haematomma in Australia

AbstractEight corticolous species of Haematomma are recognized in Australia, including four new species (H. eremaeum, H. pruinosum, H. sorediatum and H. stevensiae spp. nov.) and one new combination (H. infuscum). The characters found useful in differentiation of the species included apothecium form, apothecial pigmentation, spore septation, and thallus chemistry. Taxonomic and distributional data are provided for all species. Two taxa are reduced to synonymy for the first time, and a key is provided.