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Featured Fungus Number 21

Taphrina johansonii
A pathogen on female caktins of trembling aspen

Female catkins of trembling aspen ( Populus tremuloides) each bear dozens of capsules containing seeds. Capsules infected by Taphrina johansonii, an ascomycete, become swollen and are discolored yellow to orange, whereas non-infected capsules remain pale green. On trembling aspen, T. johansonii and the phylogenetically-allied Taphrina populina induce disease on capsules and leaves, respectively.  Several other Taphrina species also cause malformation and discoloring of leaves or catkins of trees in the Salicaceae.  Click on the accompanying photo for detailed information specific to T. johansonii, and for information on Taphrina occidentalis, which causes red, hypertrophied catkins on red alder. [file size: 410 kb]

 

Featured Fungus Number 22

Conidia of Septoria musiva
A pathogen causing leaf spots and stem cankers of hybrid poplars and cottonwoods

Septoria musiva Peck induces leaf spots and stem and branch cankers on susceptible hybrid poplars and cottonwoods (Populus spp.). Stem cankers most commonly occur within 50 cm from ground level, and are slightly flattened, with swollen sides and sunken centers. Conidia, which are pale pink in mass, are produced from pycnidia on cankers and leaf spots.  A closely related species, S. populicola, is the frequent cause of poplar leaf spot epidemics in the Pacific Northwest. Click on the accompanying photo for detailed information on the recent finding of this pathogen in a commercial hybrid poplar nursery in British Columbia. [file size: 523 kb]

 

Featured Fungus Number 23

Umbilicaria hirsuta
A rarely encountered lichen in western North America

The lichen Umbilicaria hirsuta (Sw. ex Westr.) Hoffm. is sporadic and rare throughout western North America. The sole known Oregon population is located in the southwest part of the state on a single noncalcareous rock outcrop in a mixed coniferous/broadleaf forest at an elevation of 946 meters. This distinctive umbilicate lichen can be identified in the field by the presence of submarginal soredia. This is the only sorediate species of Umbilicaria in North America. Other characteristics include a light gray brown upper surface and a rhizinate lower surface. Click on the accompanying photograph of rhizines formed by this fungus to read the recent report from Oregon [file size: 727 kb]. 

 

Featured Fungus Number 24

Leptogium siskiyouensis
A new species from Oregon and California

Species new to science continue to be found, and not all are from tropical rainforests or deep-sea trenches. Leptogium siskiyouensis is a newly described, epiphytic lichen species occurring in southwestern Oregon and northwestern California. The small thalli grow mainly on Quercus species in open mixed conifer-hardwood forests, at elevations of between 610 and 1280 m. Characteristic of this species are the lobes that form a closely adnate, smooth, shiny, grey, circular thallus of up to 3 cm. As each lobe matures the center remains closely attached to the bark but edges raise up almost 90°. Lichens have evolved several kinds of asexual reproductive propagules, one of which is the isidium, a small projection that contains the photosymbiont and strands of fungal hyphae. Isidia detach easily from thalli and are spread by rain, wind, or animal vectors. Once in an appropriate microenvironment, each can develop into a new thallus. Isidia of L. siskiyouensis form a dense fringe along the upturned lobe edges. Visible with low magnification, they typically start as simple, narrow, knobby cylinders, becoming isodiametrically forked and then coralloid to look like upraised hands In addition, they can arise on the lobe surface where they are smaller and less coralloid than marginal isidia. To learn more, click on the accompanying photo to read the article describing this newly-discovered species. [file size: 802 kb].   

 

Featured Fungus Number 25

Leveillula taurica
An emerging plant pathogenic fungus in the Pacific Northwest

Leveillula taurica is a powdery mildew fungus that likely originated somewhere in the Mediterranean region. It has been known in North America since the early 20th century and it can be extremely damaging on crops such as greenhouse-grown tomatoes and bell peppers. Thought to occur on the widest range of hosts of any powdery mildew fungus, it occurs on plants representing more than 50 families. Beginning in the 1990's this fungus has been reported on an increasing number of hosts in the Pacific Northwest where it now appears to be well established. Unlike the case in most powdery mildew fungi which grow superficially on leaves and stems, L. taurica hyphae can penetrate host tissue. For more information about the genus Leveillula, and how to differentiate it from more commonly encountered powdery mildew genera, click on the accompanying photo that shows L. taurica hyphae encircling host cells [file size: 4062 kb]. 

 

Featured Fungus Number 26

Coelomomyces stegomyiae
A potential bio-control agent of mosquitoes

Coelomomyces is a chytrid genus in the Blastocladiomycota (see C. steogomyiae, James et al., Mycologia 98:860-871). Whisler et al., 1975 (PNAS 72:693-696.) showed that in Coelomomyces psorophorae Couch, the diploid zoospore-producing phase developed in the mosquito larvae of Culiseta inorata while the haploid gamete-producing phase developed in the copepod Cyclops vernalis. This discovery established that life cycles in the genus Coelomomyces include an alternation of generations and required two different hosts to complete its life cycle. It is now known that certain insect larvae, for example, those of mosquitoes, black flies, chironomids and tabanids, and a copepod or an ostracod are required to complete the life cycle this obligate host specific fungus parasite. Soon after Keilin's discovery of Coelomomyces stegomyiae in the larva of the mosquito Stegomyia scutellaris (agent of yellow fever) in 1921, the genus became a prime candidate for the control of mosquitoes and other insects because of its host specificity and lethal nature. Today, efforts continue on the use of Coelomomyces as a bio-control agent of insects, including various mosquitoes, the agents of malaria and other diseases. For more information on the research of Howard Whisler, click on the accompanying photo of thick-walled sporangia of C. stegomyiae releasing zoospores [ file size: 835 kb].

 

Featured Fungus Number 27

Bryoria fremontii
A forage lichen occuring in northwestern North America

Forage lichens are pendulous, hairlike species eaten by a wide range of mammals. The main course is Bryoria fremontii, which forms massive dark brown beards on conifers. Abundant in the Pacific Northwest and northern Rocky Mountains where it can achieve a biomass over 1 T/ha dry weight, this species becomes increasingly rare southward and eastward in drier habitats. The palatability of Bryoria fremontii is notable because, unlike most forage lichens, it virtually lacks the secondary chemicals that defend lichens against herbivory. Despite the ecological importance of Bryoria in western North America, studies of its response to disturbance are few. Click the photo to read a paper on how Bryoria responds to the onslaught of disease and disturbance in our forests [file size: 1033 kb].  

 

Featured Fungus Number 28

Podosphaera fusca
A widespread powdery mildew producing conidia with fibrosin bodies

Podosphaera fusca is a common powdery mildew that parasitizes a wide range of economically plant species. As in other species of Podosphaera , Cystotheca and Sawadaea, it forms conidia with fibrosin bodies. These inclusions can be rod-shaped, rhomboidal, donut-shaped, funnel-shaped, or reminiscent of commas or parentheses. Although known for many years, scientists still know little about how fibrosin bodies form, what comprises them, or what function they play in the biology of these fungi. Nonetheless, they have been shown to be useful in determining powdery mildew genera and species. For more information about classification of this and other species of powdery mildews, click on the accompanying photo. [file size: 4062 kb]. 

 

Featured Fungus Number 29

Jumillera rogersii Ju and Hsieh
A new pyrenomycete species from Taiwan

The genus Jumillera includes unusual pyrenomycetes that form synanamorphs (multiple conidial states). This new species produces asexual states classified in the form genera Geniculosporium and Libertella. The sexual state includes perithecia that contain cylindrical asci (pictured in the photograph) with amyloid apical rings, and brown ascospores with germ slits. The species was named after Professor Jack D. Rogers who has spent his career studying pyrenomycetes at Washington State University. The article describing this new species is one of a collection of papers included in the Festschrift (commemorative issue) of North American Fungi honoring Professor Rogers. For more information about Jumillera rogersii click on the accompanying photograph to view the article by Ju and Hsieh in which this species is described. [file size: 495 kb].

 

Featured Fungus Number 30

Amanita marmorata var. myrtacearum
A mushroom occurring in the Hawaiian Islands

By far the most common Amanita in the Hawaiian islands, A. marmorata var. myrtacearum is found in Eucalyptus plantations, and especially around Melaleuca, “bottle brush” or “paper bark” trees, used in landscaping in urban areas. The association of A. marmorata var. myrtacearum with introduced Myrtaceae was obvious when the grass surrounding a large planting of various species of Australian Myrtaceae at the National Tropical Garden at Lawai on Kaua'i was white with hundreds of fruiting bodies. This fungus also is common under coastal Casuarina and is presumably mycorrhizal with these trees too. For more information about this and other mushrooms in the Hawaiian Islands, click on the accompanying photo to see the article by Hemmes and Desjardin. [file size: 1853 kb]

 

Featured Fungus Number 31

Chlamydopus meyenianus
A woody desert puffball from Oregon

Dried fruitbodies (left) of this uncommon but widely distributed stalked gasteromycete are occasionally found in the sandy sagebrush lands of Oregon, Washington, and Idaho, but fresh specimens have not been collected until recently.  In 2003, a solitary soft fresh specimen with all external tissues intact (right) was collected a few days after a spring rain next to an interstate highway on the Oregon banks of the Columbia River.  A slice through the amanita-like warted cap and thick white volva exposed the mature rusty gleba characteristic of Chlamydopus. For complete information on the distribution, morphology, and development of this unusual mushroom, click on the accompanying photo to see the article by Norvell, Ammirati & Redhead. [file size: 2900 kb]

 

Featured Fungus Number 32

Tilletia secalis
A bunt pathogen occuring on cultivated rye

Two bunt fungi with reticulately ornamented teliospores, Tilletia contraversa (dwarf bunt), and T. caries (common bunt), are present on wheat and rye in most of the cool and temperate growing regions of the world. In contrast, T. secalis, the rye bunt pathogen, is widespread on cultivated rye in Europe and Eurasia but there are no confirmed reports in North America. Reports of bunt on rye in North America have been attributed to T. contraversa or T. caries. The accurate identification of bunt fungi infecting wheat and rye is complicated by their overlapping host range and similar teliospore morphology. Researchers used a multilocus phylogenetic analysis to show that a bunt fungus from a stunted volunteer rye plant growing in an Idaho wheat field is genetically distinct from the wheat bunt pathogens, and may represent the first report of T. secalis in North America. To read more about this discovery, click on the accompanying photo of teliospores for the article by Carris and Castlebury [file size: 1094 kb].

 

Featured Fungus Number 33

Fungus romanticus
An attractive but unidentified mushroom (a Russula perhaps, or a bolete?) completes a tableau of romance between two little people

Mushrooms have long been associated with fairies. In writings or art of Victorian and post-Victorian times, this association distinctly conveyed "cuteness" for both fungi and fairies. One such illustration, often reproduced, is from Doyle's In Fairyland: A Series of Pictures from the Elf World (1870). This image certainly resonates with our contemporary notion of fairies as cute, and is highly appropriate for Valentine's Day! But, cuteness was not always inherent in this relationship. Prior to their re-crafting by various Victorian artists and writers, neither fairies nor their accompanying fungi were necessarily cute or benign. To learn more about fungi and fairies, click on the accompanying illustration [file size: 1489 kb].

 

Featured Fungus Number 34

Usnea longissima
A charismatic, globally threatened epiphytic lichen

Usnea longissima Ach. occurs in cool, coastal forests in Europe, Asia and North America. The Pacific Northwest is considered to be a stronghold of the species. Secondary chemistry of U. longissima is known to be complex in other regions and appears to be variable in the central Oregon Coast Range. Using thin-layer chromatography, three chemotypes were revealed from collections made from throughout the study area. These chemotypes were statistically correlated with ecological and geographic features. Click on the photo (courtesy Dave Kofranek) to find out more about U. longissima chemotypes. [File size: 308 kb]

 

Featured Fungus Number 35

Hypogymnia beringiana
A new lichen species from the Bering Sea region

Hypogymnia lugubris ssp. beringiana was recently elevated to species status as Hypogymnia beringiana in a recent issue of North American Fungi. This was accompanied by descriptions of two other new species of Hypogymnia, H. fistulosa and H. castanea, both from the Bering Sea region. The isotype shown at left is from the U.S. National Herbarium. The characteristic black mottling on the upper surface of H. beringiana, shown in the photo inset, is shared with H. lugubris, a dominant lichen on tundra in the subantarctic. Hypogymnia lugubris ssp. beringiana was described by Hildur Krog in 1968, later the specimen label was annotated by one of America's pre-eminent lichenologists, Mason Hale. J. M. Macoun's original label indicates that the specimen was collected on St. Paul Island in the “Behring Sea” in 1897. To learn more about this and the other new Beringean species of Hypogymnia, click on the accompanying illustration. [file size: 1603 kb].

 

Featured Fungus Number 36

Seuratia millardetii
A newly reported epiphytic fungus on Camellia species

Seuratia millardetii occurs on leaves of a wide variety of plants, ranging from conifers to angiosperms. Recently it was determined to be the fungus associated with what previously was considered a sooty mold of Camellia species in Washington State. Rather than a sooty mold, this unusual species is a member of the Myriangiales sensu Barr, and forms tiny cushion-shaped to lobed colonies that are filled with round cells embedded in a gelatinous matrix. The colonies shrink as they dry, and when rehydrated swell rapidly as they absorb water. The size, composition, and behavior of the colonies during drying and rehydration is remarkably similar to microcolonial fungi reported from rock surfaces, the object of study by scientists interested in possible forms of extraterrestrial life. To learn more about this widely distributed but poorly understood fungus click on the accompanying illustration [file size: 2558 kb]. 

 

Featured Fungus Number 37

Lithophyton terrestre digitatum nigrum (AKA Xylaria digitata)
One of the first Pyrenomycetes to be studied microscopically

The accompanying illustration originally was published by Jean Marchant in 1711 to show a strange organism he collected in 1709. The name (Lithophyton terrestre digitatum nigrum) he gave to the organism is a polynomial, an archaic form of scientific name that predated Linnaeus' popularizing of binomials, the style of scientific name (consisting of a genus name and a species epithet, such as Xylaria digitata ) now used by taxonomists. By describing this organism in the genus Lithophyton Marchant followed his belief that it was a terrestrial member of the soft corals (Lithophyton continues to be used today for soft corals). Today, 200 years after Marchant collected it, the organism is recognized as a fungus. Although his original name for the fungus has fallen into disuse, biologists still regard his illustration as one of the very first to show fungal spores and perithecia. For more information about this historically noteworthy fungus, and other early illustrations of Xylaria species, click on the illustration to read the accompanying article by Pfister [file size 1008 kb].  

 

Featured Fungus Number 38

Phaeocollybia longistipitata )
A recently described new species from Costa Rica

 

Costa Rica long has been recognized by scientists as a hotspot of biodiversity. The country also is a leader in inventorying the organisms that occur there. Research facilitated by the Costa Rican National Biodiversity Inventory, a multinational project coordinated by the Costa Rican National Biodiversity Institute (INBio), has documented a very diverse community of macrofungi including many species previously unknown to science. One of the new species discovered there is the aptly named Phaeocollybia longistipitata (the species epithet “ longistipitata ” refers to the long stipe or stem of the mushrooms). It occurs in high elevation cloud forests in the Talamanca Mountains where it grows in decomposing litter and debris. Interestingly, it bears superficial similarity to Phaeocollybia species found in Mexico, New Zealand, the North American Pacific Northwest, and Papua New Guinea. For more information about this interesting fungus, click on the accompanying photograph to see the article where it was first described by Halling and Horak [file size 4036 kb].   

 

Featured Fungus Number 39

Hypoxylon urriesii J. Fournier & M. Stadler
A recently described new species from the Canary Islands

 

The genus Hypoxylon includes numerous species of Ascomycetes found throughout the world on live or decomposing plants. Classification of Hypoxylon species is evolving rapidly. New data from electron microscopy, gene sequences, and secondary metabolite profiles now complement morphological information obtained with light microscopy. For example, the recently described species Hypoxylon urriesii is superficially similar to H. rubiginosum but can be distinguished on the basis of morphological features and HPLC profiles. The accompanying photograph shows asci and ascospores in a squash mount made from the type collection of H. urriesii. It illustrates nicely how ascospores change from being nearly colorless to dark brown as they mature. For more information about H. urriesii, and the use of secondary metabolite profiles in the classification of Hypoxyon species, click on the accompanying photo to see the article by Stadtler and coauthors [file size 1947 kb].

 

Featured Fungus Number 40

Xylaria oxyacanthae
An unusual seedborne fungus

 

Xylaria oxyacanthae occurs in Europe and North America where it is found fruiting on seeds of species of Crataegus or Carya . It has received attention from mycologists for many years, including pioneering 19 th century work by the Tulasne brothers, but it has been unclear as to how and when the fungus colonizes seeds. In a recent research project, X. oxyacanthae was isolated from 2-3% of fruits removed from Crataegus monogynus trees, indicating that they were infected while still on the trees. Conidial stromata formed from decayed fruit under flowering trees, suggesting the possibility that flowers are infected by conidia. For more information about this fungus and its unusual life cycle, click on the accompanying photo of white conidial stromata (scale bar = 1 cm). [file size: 576 kb]