Roland Thaxter Research Articles

Insects and their Laboulbeniales (Ascomycota, Fungi) of Lake Eustis and Emeralda Marsh Conservation Area: A case study on urbanization and diversity.

A rapid biodiversity assessment of insects and associated Laboulbeniales fungi was conducted over the course of five nights in August, 2018, at two central Florida lakes: Lake Eustis and the nearby protected and restored National Natural Landmark, Emeralda Marsh Conservation Area (EMCA), which encompasses a portion of Lake Griffin. Lake Eustis was surveyed for Laboulbeniales in 1897 by mycologist Dr. Roland Thaxter but has not since been investigated. Because Lake Eustis has been urbanized, with the lake perimeter almost entirely altered by human development, the site offers a look into Laboulbeniales diversity across a 121‐year timeline, before and after human development. By surveying Lake Eustis and EMCA, a modern case study comparison of Laboulbeniales and insect diversity between a developed and a protected and restored system is made. A total of 4022 insects were collected during the rapid assessment. Overall, insect abundance was greater at EMCA, with 3001 insects collected, than 1021 insects collected from Eustis. Although family‐level insect richness was comparable between sites, with 55 families present at EMCA and 56 at Eustis, 529 out of 3001 (17.6%) of the insects collected at EMCA were hosts to parasitic Laboulbeniales fungi, whereas only 2 out of 1021 (0.19%) collected from Eustis were infected. A total of 16 species of Laboulbeniales found at EMCA compared with only one at Eustis. The current number of Laboulbeniales species documented at Eustis was incredibly depauperate compared with the 26 species and two varieties recorded by Thaxter in 1897. These findings suggest the possibility of utilizing Laboulbeniales as indicators of ecosystem health, and future research should investigate this question further. A figure displaying host–parasite records and a species list of Laboulbeniales are presented. Finally, updated occurrence records for species of Ceratomyces and Hydrophilomyces are provided.

Laboulbeniales (Ascomycota) of the Boston Harbor Islands II (and Other Localities): Species Parasitizing Carabidae, and the Laboulbenia flagellata Species Complex

This paper presents 13 new records of Laboulbenialean parasites on ground beetles (Coleoptera, Carabidae) from the Boston Harbor Islands National Recreation Area in Massachusetts: Laboulbenia anoplogenii, L. casnoniae, L. clivinalis, L. egens, L. filifera, L. flagellata, L. inflata, L. macrotheca, L. pedicellata, L. terminalis, L. variabilis, L. vulgaris, and Peyritschiella geminata. Laboulbenia clivinalis and L. egens are new country records for the US. Moreover, we present additional localities for L. casnoniae, L. clivinalis, L. filifera, L. flagellata, L. inflata, L. pedicellata, L. variabilis, and L. vulgaris. The following new country records are presented: Laboulbenia clivinalis, L. filifera, and L. variabilis from Canada; L. flagellata from the Democratic Republic of the Congo; L. pedicellata from Ukraine; L. vulgaris from Croatia and Slovenia (and the first undoubtful record from Slovakia). Laboulbenia flagellata was found on 11 host species in the genera Agonum, Oxypselaphus, Patrobus, Platynus, and Pterostichus. Using this abundant material, we performed morphometrics to test the hypothesis that L. flagellata is a species complex. Specimens cannot be separated based on host genus (Agonum, Pterostichus). One parameter is significant between Pterostichus mutus and each of the 4 Agonum species after applying a strong Bonferroni P-value correction: H1T, the ratio of height of cell I (HC1) to total thallus length (TTL). In addition, we collected fresh material to be able to add a molecular phylogenetic component to test said hypothesis. We generated ITS and nrLSU ribosomal sequences of several species of Laboulbenia, including isolates of L. flagellata from multiple hosts. Phylogenetic inference of the concatenated dataset shows that L. flagellata isolates from 3 host species form 2 distinct clades, providing support for our hypothesis. We also show that L. coneglianensis is separate from L. flagellata, unequivocally ending a long-standing taxonomic debate. Finally, examination of Roland Thaxter's 1891–1932 slides led to the designation of lectotypes for L. macrothecia, L. terminalis, and P. geminata.

Notes on Syncephalis (Zoopgales, Zoopagomycota) from the Farlow Herbarium, with the description of a new species, Syncephalis aethiopica

ABSTRACTThe Harvard mycologist Roland Thaxter collected and studied a wide variety of fungi. Although he described >1000 fungal species, he was unable to describe all the specimens he collected before his death in 1932. His collections and microscope slides remain an important resource for studying fungal diversity at the Farlow Herbarium at Harvard University. Thaxter described three species in the obligate mycoparasite genus Syncephalis: S. pycnosperma, S. tenuis, and S. wynneae. He retained slide mounts of several other species, including a new species from his collection that was not described. Here, we describe that new species as S. aethiopica based on morphological analysis of his preserved slides. We also discuss the morphology of S. reflexa, a species apparently only known from slides preserved at the Farlow Herbarium.

A systematic overview of Descolea (Agaricales) in the Nothofagaceae forests of Patagonia

The descolea clade includes species of ectomycorrhizal basidiomycetes in the genera Descolea, Setchelliogaster, Descomyces, and Timgrovea that are known primarily from the Southern Hemisphere. Taxa in this group produce basidiomes that range in morphology from typical epigeous mushrooms (Descolea) and secotioid taxa (Setchelliogaster) to fully gasteroid species (Descomyces and Timgrovea). High intraspecific morphological variation has been reported in several species within this clade, suggesting that careful morphological and molecular studies are needed to refine species concepts. Molecular analyses of fresh Patagonian collections in conjunction with taxonomic studies have confirmed high variability in key morphological features, including overall sporocarp form, spore shape and dimensions, universal veil remnants, and cuticle configuration. Based on our synthesis, we emend the genus Descolea to include sequestrate species. We describe the new sequestrate taxon Descolea inferna sp. nov. from Nothofagaceae forests in Patagonia and we propose Cortinarius squamatus as a synonym of our new combination Descolea brunnea. We also formalize the identity of Descolea pallida as a synonym of Descolea antarctica and provide new specimens of Cortinarius archeuretus, a species that has not been encountered since the original discovery during the expeditions of Roland Thaxter in 1905–1906. Here we re-describe and transfer this species to Descolea as D. archeureta. We also discuss diagnostic features that can be used to delimitate the four known South American taxa in the descolea clade.

Fireworks under the microscope: a spectacular new species of Zodiomyces from the Thaxter collection

A new species of Zodiomyces (Ascomycota, Laboulbeniales) is described, Z. rhizophorus, parasitic on a hydrophilid beetle (Coleoptera, Hydrophilidae) from Trinidad. This species was discovered during the examination of the slides of Laboulbeniales made by Roland Thaxter. It is characterized by numerous long, slender, multicellular and multiseriate outgrowths at the base of the receptacle. Thaxter’s outstanding illustrations have set a standard in the field of mycology; we provide a review of the methods he employed in the preparation of these illustrations.

Laboulbeniales (Ascomycota) of the Boston Harbor Islands I: Species Parasitizing Coccinellidae and Staphylinidae, with Comments on Typification

This paper, based on a recent comprehensive sampling of insects, is the first report of Laboulbeniales from the New England region since the 1930s. We present 7 new records of laboulbenialean parasites on Staphylinidae (rove beetles) and Coccinellidae (lady beetles) from the Boston Harbor Islands National Recreation Area. These are Clonophoro- myces nipponicus Terada & I.I. Tav., Hesperomyces virescens Thaxt., Ilyomyces cf. mairei F. Picard, Laboulbenia philonthi Thaxt., Peyritschiella protea Thaxt., Stichomyces conoso- matis Thaxt., and Teratomyces actobii Thaxt. One of these parasite species, C. nipponicus, has not been found previously outside of its type locality in Japan. Examination of Roland Thaxter's 1891-1932 slides led to the designation of lectotypes for L. philonthi, P. protea, S. conosomatis, and T. actobii. The following synonymy is established: Teratomyces brevi- caulis Thaxt. = T. actobii. In addition, we discovered new localities for H. virescens (from Canada, Cuba, Guatemala, and Japan) and L. philonthi (from Canada, Grenada, Panama, Trinidad, and Venezuela).

Three new species of Laboulbenia from Roland Thaxter’s backlog of slides and a brief review of Laboulbeniales associated with Chrysomelidae

Three new species of Laboulbenia parasitic on Chrysomelidae are described from material mounted by Roland Thaxter (1858–1932). These are L. bilobata on Lema spp. from Brazil and Trinidad; L. longipilis from Cameroon; and L. pfisteri on Ivongius sp. from Madagascar. The following species of Laboulbenia on Chrysomelidae are illustrated for the first time: L. macarthurii, L. minuscula, L. nodostomatis, L. obesa, and L. philippina, all of which were described by Thaxter in 1914. A list of all 69 described Laboulbeniales associated with Chrysomelidae is presented in tabulated form.

Position specificity in Chitonomyces (Ascomycota, Laboulbeniomycetes) on Laccophilus (Coleoptera, Dytiscidae): a molecular approach resolves a century-old debate

The occurrence of Laboulbeniomycete species consistently on a precise portion of beetle integument was investigated in 13 species of Chitonomyces ectoparasitic on the aquatic diving beetle Laccophilus maculosus (Coleoptera, Dytiscidae). The phenomenon was called “position specificity” by Roland Thaxter in 1896, yet the mechanism has remained unknown. By using molecular analysis of the nucSSU rRNA gene and the 5.8S and partial ITS1 rRNA regions, 13 species of Chitonomyces reported to exhibit position specificity on Laccophilus maculosus were placed neatly into pairs of morphotypes, resulting in synonomies and recognition of six phylogenetic species (one species is a triplet). Each phylogenetic species was located at corresponding positions on male and female beetles that make contact during mating. In addition, ecological data and video footage of the mating behaviors of Laccophilus confirmed that sexual transmission is the mechanism behind this enigmatic phenomenon.

Lingering Puzzles about Myxobacteria

The myxobacteria are social and capable of constructing intricate macroscopic structures called fruiting bodies. First recognized as bacteria in 1892 by the cryptogamic botanist Roland Thaxter, these exotic anomalies have proved challenging to microbiologists. Even so, we now know a great deal about the nutrition, life cycle, growth physiology, intermediary metabolism, structural chemistry, genetics, and regulatory pathways of one of the myxobacteria, Myxococcus xanthus. Despite such progress, however, the myxobacteria leave us with several outstanding puzzles, including: How do fruiting bodies form? What is the function of “A,” or adventurous, gliding motility, and how is “S,” or social motility coordinated? How can we understand the cellular morphogenesis of myxospore formation and germination? What mechanisms control M. xanthus swarming behavior? What is the ecological role of the myxobacteria?

Dirina calcicola, a New Lichen Species from Florida, U.S.A

Abstract A new species in the lichen genus Dirina (Ascomycota: Arthoniales: Roccellaceae) is described. It is similar to Dirina neozelandica and related species in the genus with immersed ascomata lacking a thalline margin. Dirina calcicola is only known from two specimens collected in 1898 by Roland Thaxter in Monroe Co., Florida, U. S. A.

Roland Thaxter's legacy and the origins of multicellular development.

Roland Thaxter's legacy and the origins of multicellular development.

Cupulomyces, A New Genus of Laboulbeniales (Asomycetes) Based on Stigmatomyces Lasiochili

A new genus of Laboulbeniales, Cupulomyces, is described. Its type species, C. lasiochili, is based on Stigmatomyces lasiochili, originally described by Roland Thaxter in I 917. This taxon subsequently has been classified in two other genera, Hesperomyces and Acompsomyces. Structure and development of the thallus of C. lasiochili are described and illustrated with photographs and line drawings. Distinctive features of the receptacle, appendage, and perithecium warrant recognition of a new genus.

Some Hepaticae collected by Dr. Roland Thaxter in Chile, 1905-1906

Some Hepaticae collected by Dr. Roland Thaxter in Chile, 1905-1906

Two New Fifty-Year-Old Species of Myxobacteria

(1958). Two New Fifty-Year-Old Species of Myxobacteria. Mycologia: Vol. 50, No. 5, pp. 628-633.

Cordyceps Stylophora and Cordyceps Ravenelii

Cordyceps stylophora was collected by Ravenel in South Carolina and was described and illustrated by Berkeley in 1857 (1). Ravenel distributed it in his Fungi Car. V: 49. It has been rarely collected. It was next obtained by G. H. Hicks in April 1892 near the Michigan Agricultural College at East Lansing, Michigan. A part of this collection is in the Herbarium of the University of Michigan and bears a notation that it was determined by Ellis. Longyear (3) reported it in 1904. Roland Thaxter collected a specimen in August 1896 at Burbank, Tennessee (4). Petch (7) has reported a collection (Cornell 14808) by H. H. Whetzel from Cayuga Lake Basin, New York, made in November 1902. L. E. Wehmeyer obtained two specimens at Brookside, Nova Scotia, on July 25, 1931. A. H. Smith made a number of collections at Warrenburg and Catlin Lake, New York, during August and September 1934 and from Oakland County, Michigan, in August and September, 1937 and October 1938. Most of the collections were In the original description of the species Berkeley states that he had not seen ripe asci. Massee (6) described the asci and spores. The latter are given as filiform, slightly curved when free, multiseptate, 125135 X 1 ~, the component cells 3.5 A long. He cites only the type specimen, Ravenel 1325. Petch (7), however, states that he examined the type specimen and it was quite immature. The Cornell specimen was also found to be Mains (5) has also noted that most of the collections from Tennessee, New York and Michigan were The Hicks' specimen was the nearest to full maturity, the asci being well developed and the ascospores

Some New Species of Hypoxylon

The descriptions of the following new species of Hypoxylon are based on specimens sent the writer by Dr. Roland Thaxter and Prof. A. S. Muller, and others of his own collecting. The forms which are given varietal names do not differ from the established species in sufficient characters to warrant specific rank. In most cases they are distinct only in ascospore dimen? sions. This latter character varies considerably with material of different ages, but there is a fairly definite maximum limit. For example, Hypoxylon serpens Pers. ex Fries has ascospores which vary in length from 10 to 15 /x. This species was described from Europe and all material examined there falls within these limits. In America, however, the European form is very com? mon, but occasionally one finds what is apparently the same thing except for the much larger ascospores; that is, between 15 and 20 ix, in length. These variants may be mutants or hybrids, but in view of the present lack of knowledge of inheritance in the fungi, it seems best to give them varietal rank.

Prof. Roland Thaxter

PROF. ROLAND THAXTER, of Harvard, died on April 22, at the age of seventy-three years. He was born at Newton, Mass., on Aug. 28,1858, and graduated at Harvard University in 1882, proceeding to post-graduate work there until he was appointed mycologist at the Connecticut Experimental Station in 1888. Three years later he returned to Harvard as assistant professor of cryptogamic botany, becoming professor in 1901. He retired in 1919 with the title of emeritus professor, and acted as honorary curator of the Farlow Herbarium. Such is the bare outline of the career of one whose work in mycology is classical. His first researches were on the rust Gymnosporangium, but he published an account of the entomogenous family Entomopthoreæ in 1888, which still remains one of the most important papers on the group. A few phytopathological reports appeared while he was at Connecticut, some of considerable interest. In 1890 he made his first contribution to our knowledge of the peculiar entomogenous fungi, the Laboulbeniaceæ, and it is with these that his name is chiefly associated, for from being almost unknown, they became, owing to Thaxter's enthusiasm, a group as well understood as any other and containing hundreds of genera and thousands of species.

Some Observations on the Development of Endogone malleola Hark

Summary1. There is great variation in the sporangiocarps of E. malleola. Large and small sporangial types of fructifications are noted.2. The spores germinate readily in water.3. By means of anastomoses larger distributive hyphae develop.4. Protoplasmic movement is very rapid in the distributive hyphae.5. Large masses of firmly interwoven moniliform cells superficially resembling sporangiocarps develop on cultures, but true sporangiocarps were never produced.6. The development of the sporangia is entirely phycomycetous.7. A close relationship between E. malleola and Mortierella is noted.I wish to express my indebtedness to Dr. Roland Thaxter for suggestions during the progress of my work and for reading a first draft of this paper and adding more helpful suggestions. Thanks are also due Dr. Thaxter and Dr. E. A. Burt for identifications and Prof. T. J. Fitzpatrick for proof-reading the paper.

Ants collected in Trinidad by Professor Roland Thaxter, Mr. F. W. Urich, and others.

Ants collected in Trinidad by Professor Roland Thaxter, Mr. F. W. Urich, and others.

Myxomycetes from South America

Our knowledge of the Myxomycetes of South America is comparatively meager. Spegazzini's numerous articles upon the fungi of Argentina, Brazil, Uruguay, and Paraguay1 contain references to Myxomycetes and describe a number of new species, several of which, however, appear, on closer examination, to be referable to already known forms. R. E. Fries2 has listed 47 species from Argentina and Bolivia. From Brazil, Berkeley and Curtis,3 Hennings,4 Jahn,5 von Hohnel,6 and Sydow7 have published brief lists. Johows mentions a few species belonging to this group in his Flora of Juan Fernandez, Chile. Ecuador is represented by a small number included by Patouillard and Lagerheim in their Champignons de l'fquateur,9 while the former observer, in collaboration with Gaillard, reports i species of Myxomycetes in his Champignons du Venezuela.10 Although practically all parts of South America are represented in the publications of the above observers, the number of actual species of Myxomycetes listed is surprisingly small. It is therefore gratifying to be able to add materially to our knowledge in this field. The following species were collected by Professor Roland Thaxter in Argentina and Chile in I905-o6. The collection is deposited in the Cryptogamic Herbarium of Harvard University, and it is through the courtesy of Professor Thaxter and Dr. W.