Taxa named by Margaret Elizabeth Barr-Bigelow

The Pleosporales is the largest order in the fungal class Dothideomycetes. By a 2008 estimate, it contained 23 families, 332 genera and more than 4700 species. The majority of species are saprobes on decaying plant material in fresh water, marine, or terrestrial environments, but several species are also associated with living plants as parasites, epiphytes or endophytes. The best studied species cause plant diseases on important agricultural crops e.g. Cochliobolus heterostrophus, causing southern corn leaf blight on maize, Phaeosphaeria nodorum (Stagonospora nodorum) causing glume blotch on

The Chaetothyriales are an order of ascomycetous fungi in the class Eurotiomycetes and within the subclass Chaetothyriomycetidae. The order was circumscribed in 1987 by mycologist Margaret Elizabeth Barr-Bigelow.

The Chaetosphaeriaceae are a family of fungi in the Ascomycota, class Sordariomycetes. The family was circumscribed by Martina Réblová, Margaret Elizabeth Barr Bigelow, and Gary Samuels in 1999. Species in the family have a cosmopolitan distribution, and are found in both temperate and tropical climates. Fossils of the Chaetosphaeriaceae are known from the Carboniferous, Eocene, Oligocene, Miocene and more recent sediments.

The Calosphaeriales are an order of fungi within the class Sordariomycetes containing 2 families. They are saprophytes and have small fruiting bodies.

The Phaeosphaeriaceae are a family of fungi in the order Pleosporales. Species in the family have a cosmopolitan distribution, and are generally nectrotrophic or saprobic on a wide range of plants.

The Trichosphaeriales are an order of sac fungi. It is monotypic, and consists of the single family, the Trichosphaeriaceae. In 2017, the family of Trichosphaeriaceae was placed in Diaporthomycetidae families incertae sedis, which was accepted by Wijayawardene et al. (2018), and Wijayawardene et al. 2020. The order of Trichosphaeriales was also unplaced. They are generally saprobic and pathogenic on plants, commonly isolated from herbivore dung.

The Chaetothyriaceae are a family of ascomycetous fungi within the order Chaetothyriales and within the class Eurotiomycetes. A 2012 molecular analysis of specimens collected from northern Thailand revealed three new species in the family (Ceramothyrium thailandicum, Chaetothyrium brischofiacola and Phaeosaccardinula ficus).

The Leptosphaeriaceae are a family of fungi in the order Pleosporales. The family was circumscribed by mycologist Margaret E. Barr in 1987. According to the Dictionary of the Fungi (10th edition, 2008), the family contained 8 genera and 302 species. The family has a widespread distribution, but is especially prevalent in temperate regions. Species are either saprobic or grow as nectrotrophs (organisms that grow and reproduce on dead cells) on the stems or leaves of plants.

The Planistromellaceae are a family of fungi, with in the order Botryosphaeriales.

The Tubeufiaceae are a family of fungi in the order Tubeufiales of the class Dothideomycetes. The family was circumscribed in 1979 by mycologist Margaret Elizabeth Barr-Bigelow.

The Delitschiaceae are a family of fungi in the order Pleosporales. Taxa are widespread, especially in temperate regions, and are saprobic, often found growing in herbivore dung.

The Pleomassariaceae are a family of fungi in the order Pleosporales. Taxa have a widespread distribution in both temperate and tropical regions, and are saprobic or necrotrophic on wood, bark, and other herbaceous material. The genus was circumscribed by mycologist Margaret Elizabeth Barr-Bigelow in 1979.

The Teichosporaceae are a family of fungi in the order Pleosporales.

The Parodiellaceae are a family of fungi with an uncertain taxonomic placement in the class Dothideomycetes. It contains the single genus Parodiella, which has four species.

The Apiosporaceae are a family of fungi in the Ascomycota. It was placed in the order Amphisphaeriales in 2020.

Jobellisia is a genus of fungi within the monotypic family Jobellisiaceae and the monotypic order Jobellisiales and also the subclass Hypocreomycetidae, and class Sordariomycetes. The genus was circumscribed by Margaret Elizabeth Barr-Bigelow in 1993 with Jobellisia luteola as the type species. It contains species that grow on dead wood and bark in tropical and temperate regions of the Northern Hemisphere.

Phaeochoraceae is a family of sac fungi in the order Phyllachorales.

Immotthia is a genus of fungi in the family Roussoellaceae.

Lewia is a genus of fungi in the family Pleosporaceae.