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Results tagged “fungi”

Jul 25, 2014: Geastrum triplex

Today we feature the fungus Geastrum triplex, commonly known as the saucered or collared earthstar. These images (image 1 | image 2) were taken recently at the State Botanical Garden of Georgia and uploaded to the Botany Photo of the Day Flickr Pool by Hugh Nourse (aka Hugh and Carol Nourse@Flickr). Thanks for sharing, Hugh!

Geastrum triplex, of the Geastraceae, is an earthstar fungus. The earthstars are comprised of the genera Geastrum, Astraeus, and Myriostoma. Earthstars are modified puffballs that have a thick outer skin that splits into star-like rays (Geastrum saccatum was featured on Botany Photo of the Day in 2011). The rays, after splitting, often curve to expose the spore case (inner skin) for spore dispersal. Some earthstars are hygroscopic, though, most geastrums (including Geastrum triplex) are not. After the rays split, the central region of Geastrum triplex often (not always) breaks loose to form a broad cup or saucer around the flattened spore case. The spore case of the saucered earthstar is not elevated on a stalk (like others in the genus), and holds powdery, brown spores that are round and warted.

Geastrum triplex is a saprobic (feeding on dead or decaying matter) fungus that is widely distributed across North America. It grows alone or in groups in forest humus, often under hardwood trees. This species (like all earthstars) is noted to be difficult to find when immature because individuals are inconspicuous, and often develop underground. If you do happen to find this fungus when it is young (white inside), it is considered edible according to Mushrooms Demystified by David Arora. When they are older (and easier to find), they are apparently often too tough and fibrous to eat.

Jul 3, 2014: Amelanchier canadensis and Gymnosporangium sp.

Amelanchier canadensis and Gymnosporangium sp.

Taisha is again the author, and she writes:

Long-time BPotD reader and occasional contributor Wouter Bleeker of Ottawa, Ontario, Canada sent along today's photograph. It shows the fruits of an Amelanchier canadensis plant infected by a species of rust fungus from the genus Gymnosporangium. Thanks for sharing again, Wouter.

Rusts (order Pucciniales) are obligate plant parasites, i.e., they require plant hosts. Species of rusts often have multiple means of reproduction, each associated with a different stage in the life-cycle. Up to five different mechanisms for bearing spores (spermagonia, aecia, uredinia, telia, and basidia) are known for some species. These species of rusts require two specific and unrelated host vascular plant species: an aecial host (for spermagonia and/or aecia) and a telial host (for uredinia, telia, and basidia). Rust fungi taxa that require two hosts are called heteroecious. Some taxa, however, carry out their full life-cycle on only one host species (macrocyclic). Other rust species simply reproduce asexually with a single repeating life stage. More variations on the pattern include microcyclic (having only the telial and basidial stages and live on aecial hosts of macrocyclic relatives) or demicyclic (missing the uredinial life stage).

The Gymnosporangium clade has an array of life cycles (gif), host taxa, and degrees of host-specificity. Gymnosporangium species have a demicyclic life cycle, with most alternating between members of the Cupressaceae as a telial host (telia are gelatinous due to long pedicels of teliospores absorbing water in spring rains), and species from the Rosaceae supertribe Pyrodae (PDF) as aecial hosts (see: Novick, R. (2008). Phylogeny, taxonomy, and life cycle evolution in cedar rust fungi (Gymnosporangium)(Doctoral dissertation). Retrieved from ProQuest Dissertations and Theses. (3317188)).

In the above photograph, the Gymnosporangium species is parasitizing a member of the Pyrodae, Amelanchier canadensis. This deciduous shrub species has a number of common names including shadbush, serviceberry, and juneberry. When members of the genus Amelanchier are infected by species from Gymnosporangium, symptoms include brownish-orange spots on leaves and distorted fruits with horn-like protrusions.

According to the Horticulture Diagnostic Laboratory at Cornell University (PDF), of the 36 species of Gymnosporangium that occur in North America, only three are significant in the northeast area to warrant concern. The three species includes the cedar-apple rust (Gymnosporangium juniperi-virginianae), quince rust (Gymnosporangium clavipes), and hawthorn rust (Gymnosporangium globosum). Unfortunately, we're unsure which species is shown in the photograph submitted, but it could be quince or hawthorn rust. This is inferred from Penn State's fact sheet on cedar apple and related rusts. Both publications mention that the best way of preventing cedar rust diseases is to simply avoid planting alternate hosts close together. Planting resistant cultivars is another strategy. These management means should be employed before considering the use of fungicides.

Jan 27, 2014: Xylaria polymorpha

Xylaria polymorpha

Taisha is the author of today's entry. She writes:

Today's image is of the fungus Xylaria polymorpha, or, as its commonly refered to, dead man's fingers. This photo was taken by Marianne (aka marcella2/tovje@Flickr) in 2006. Thanks Marianne, for the photo!

This saprotrophic fungus is widely distributed in deciduous forests of North America and Europe. The mycelium of Xylaria polymorpha (Xylariaceae) secretes a mixture of extracellular digestive enzymes on the woody material on which it grows, then absorbs the digested products for fuel to grow and reproduce. Brown to dark grey fruiting bodies arise in the spring. The fruiting bodies will emerge in groups resembling fingers or a hand and darken with age, hence the common name. Within the fruiting bodies are the perithecia, where spores are produced within the asci. The fruiting bodies may persist for several months, releasing the ascospores over time in the autumn or early winter.

Xylaria polymorphya is often used for spalting wood. Spalting is the colouration of wood through fungal colonization. This effect is valued by woodworkers for the aesthetic appeal and uniqueness. In recent times, spalting has been induced by the inoculation of fungi on wood. There are three main types of spalting: 1) bleaching (caused by white rot fungi); 2) pigmentation (caused by the coloured mycelium of some fungi); and 3) zone lines (caused by the formation of a barrier by one fungus to protect its resources from another, or delineate individuals from the same isolate). Xylaria polymorpha creates zone lines by producing melanin-type pigments. These blackish pigments act as a protective barrier, surrounding the fungal community and thereby blocking water exchange within the wood substrate (see: Robinson S.C., et al. 2009. Effects of substrate on laboratory spalting of sugar maple. Holzforschung. 63(4): 491, or, Tudor, D.et al. 2012. The influence of moisture content variation on fungal pigment in spalted wood. AMB Express. 2:69).

Botany resource link (added by Daniel): Botanical Accuracy, where "botanical mistakes in commercial and public venues and products are showcased and corrected". Some very interesting stories and prominent mistakes, all documented by Dr. Lena Struwe and guest posters. Discovered via Graham Rice's Transatlantic Gardener weblog.

Nov 21, 2013: Puccinia monoica

Puccinia monoica

Taisha wrote this entry:

Today's image is of the rust Puccinia monoica (Pucciniaceae) growing on a host plant, Smelowskia calycina (Brassicaceae). It was taken by Anne Elliott (aka annkelliott@Flickr), a regular contributor to the Botany Photo of the Day Flickr Pool. Thanks Anne! Doug Waylett also has photographs of Puccinia monoica on Flickr, including these: photo 1 and photo 2.

Puccinia monoica is macrocyclic (producing 5 different kinds of spores during its life cycle: pycniospores, aeciospores, urediniospores, teliospores and basidiospores). The species is also heteroecious, meaning it requires two unrelated hosts to complete its life cycle. For Puccinia monoica, the aeicial stage host is from the Brassicaceae, while the telial host is from the Poaceae.

I decided to write about a rust fungus, particularly one from the genus Puccinia, as I recently submitted a research proposal for my weed science class (I mentioned this class in the post on Fallopia convolvulus), where I'm looking into the potential of using a specific rust fungus from the genus Puccinia as a biological control agent to suppress a weedy Caryophyllaceae species that is common both in Canada and globally. Despite some Puccinia species being used for weed control, I haven't come across any references that indicate Puccinia monoica is among them.

Biological control of weeds is when one uses a living organism to manage problematic plants. In some cases, pathogens like fungi are used. Fungal pathogens can affect their host plant's ability to compete for limited resources, reduce the growth rate of the host and/or increase susceptibility to other pests. Rust fungi have the ability to spread rapidly over large areas, are destructive, and are host specific, making them ideal candidates for use as a biological control agent against weeds. Fungi as a biocontrol agent are either used in an inoculative (classical) approach, or an inundative (mycoherbicidal) approach. The inoculative approach is a low-cost one that involves introduction of an exotic pathogen to manage a weed population over a long period of time. The inundative technique is a higher-cost method where a weed population is overwhelmed with a direct application once or many times, similar to herbicide. The pathogen in this method is often called a bioherbicide, and, if it happens to be a fungus, usually referred to as a mycoherbicide.

If you're interested in learning more you can look into Fungi as a Biocontrol Agent: Progress, Problems, and Potential by Butt, Jackson, & Magan (2001) or Non-Chemical Weed Management: Principles, Concepts, and Technology by Upadhyaya & Blackshaw (2007).

Oct 26, 2012: Cyttaria gunnii

Cyttaria gunnii

Bryant is again the author of today's entry:

Thank you to Ken Beath (aka kjbeath@Flickr) for today's image of Cyttaria gunnii (commonly known as beech orange), the next subject on the list for this series on autumn fungi. Cyttaria gunnii is an ascomycete in the family Cyttariaceae. It is a caulicolous (stem parasite) fungi, restricted to species of Nothofagus, specifically Nothofagus cunninghamii, Nothofagus fusca, and Nothofagus menziesii. The species is distributed throughout Australia, New Zealand, and Tasmania wherever host trees are also found. The fruiting bodies, which grow in clusters, are usually around 2cm in diameter. The yellow/orange cup-shaped cavities form upon maturity to release wind-dispersed spores.

If infected by Cyttaria gunnii, spherical galls are formed on the host tree. These galls remain on the branch or stem for its lifetime and provide the location for perennial fruiting every spring. Formation of the galls starts with spores germinating and subsequently penetrating the bark tissue of a nearby host, releasing chemicals as the fungal hyphae grows. These chemicals cause the unregulated proliferation of cells in the tree, much like a tumor.

Cyttaria gunnii is considered to be edible, and has been recorded as being used for food by Australian Aboriginals. It is reported to have a pleasant but slightly bland taste (again, consumption is not recommended without confirming identification with an expert).

Oct 23, 2012: Hydnellum aurantiacum

Hydnellum aurantiacum

Bryant is the author of today's entry. He writes:

For me, fall is for fungi and in this series I will cover a few of my favourite fruiting bodies!

Thank you to Anne Elliott (aka annkelliott@Flickr) for submitting today's image of Hydnellum aurantiacum via the Botany Photo of the Day Flickr Pool.

Hydnellum aurantiacum (commonly known as the orange tooth fungus) is an inedible member of the Bankeraceae. As the common name suggests, it has spines (or teeth) on the underside of the cap--these range from 2-5mm in length. The upper side of the mature cap is flat or slightly depressed, and 3-10cm (~1"-4") wide with coarse protrusions and sometimes aborted micro-caps (as seen in the centre of the one in today's photograph). The surface of this particular specimen is slightly reminiscent of 3-dimensional sound maps or spectrograms (via the weblog Bassoon Operator). In young specimens, the margin of the cap and spines is distinctly whitish in colour, a key feature for distinguishing this species from other orange and red Hydnellum species.

Hydnellum aurantiacum is mycorrhizal with conifers, primarily with pines and eastern hemlock in eastern North America, and firs and Douglas-fir in western North America. However, the species has also been observed growing under hardwoods. It is widely distributed in North America and some parts of Europe, but there has been a decline in sightings of this species in the United Kingdom. It has recently been labeled as critically endangered there. To learn more about recent declines of toothed fungi in Caledonian Forest habitat and actions to prevent further loss, visit Pinewood Tooth Fungi @ Trees For Life.

Aug 23, 2012: Plectania campylospora

Two Australian photographers to thank for today's photographs: kjbeath@Flickr aka Ken Beath is responsible for this photograph and Rotuli@Flickr contributed the other image. Both were submitted via the Botany Photo of the Day Flickr Pool. Thanks to both of you!

Plectania campylospora, or brown forest cup, is native to southeastern Australia and New Zealand, even though most species of Plectania are typically found in temperate areas of the Northern Hemisphere. I've not had much luck tracking down the origin of Plectania, but the prefix plecto- means "twisted". The epithet campylospora is generated from campylo- meaning "bent" and -spora, "spores", a characteristic noted in JD Hooker's Flora Antarctica: the Botany of the Antarctic Voyage (published in 1855): "Sporidia oblong, strongly curved, 1/750 in. long". Microphotographs of the curved spores are available via New Zealand's Landcare Research: Plectania campylospora.

Plectania campylospora is a species of wet forests, where it inhabits rotting wood.

Jun 20, 2012: Chondrostereum purpureum

Chondrostereum purpureum

An entry written by former 2011-2012 work-study student Katherine that I had squirreled away today. She writes:

Today, we have a lovely purple fungus known as Chondrostereum purpureum or silverleaf fungus. Many thanks to Marianne (aka marcella2/tovje@Flickr) for this wonderful image of Chondrostereum purpureum covered in exuding water droplets (via the UBC Botany Photo of the Day Flickr Pool). Please see a previous Botany Photo of the Day entry on Fomitopsis pinicola for more on guttating fungi.

Some of you may be familiar with Chondrostereum purpureum, or at least the disease it causes in trees (silverleaf), as this fungus can be parasitic on a number of ornamental and/or orchard woody species, particularly those in Prunus (cherries & plums and more), Malus (apples) and Pyrus pears. A clear explanation of silverleaf disease is provided by New Zealand's Horticulture and Food Research Institute.

Another common name for Chondrostereum purpureum is violet crust, as individuals starts their growth as a crust on exposed sapwood, then develop to be about 3cm in width with a "tough rubbery texture", according to the Wikipedia entry. Subsequently, the crust "dries out, becomes brittle, and turns a drab brown or beige" with the "infected wood [...] stained a darker tint".

In addition to rosaceous woody plants, Chondrostereum purpureum can also infect many other broad-leaved species (and even a few conifers), giving the species an extensive global distribution (mirroring to a large extent its host plants).

Chondrostereum purpureum is not considered edible. However, it does have an effective economic use in inhibiting resprout and regrowth of cut tree stumps. This application of the fungus can particularly be used by the electrical industry for stumps near power lines. The species is also undergoing testing as a possible control for competing vegetation in conifer plantations by the British Columbia Ministry of Forests and Range (though given how easily fungi spread, one wonders if this could have deleterious effects on the British Columbia orchard industries, even with assurances that this "mycoherbicide is restricted to the target vegetation").

For those interested, MycoBank.org provides microscopic and spore descriptions for their available cultures of Chondrostereum purpureum.

May 3, 2012: Coccomyces dentatus

Coccomyces dentatus

We'll be starting a series from Katherine either tomorrow or Monday on "white-flowered medicinal plants". That series will, for the most part, conclude her contributions as a work-study student. Today's article, though, is written by Bryant Deroy, who is joining us as a work-study student over the summer (funded by your many kind contributions). Bryant writes:

A big thank you to Richard Droker for this striking image of Coccomyces dentatus, which has colonized the dead leaf of a Berberis nervosa (syn. Mahonia nervosa).

Information on Coccomyces dentatus is extremely hard to come by and some sleuthing was required to dig up the details on this species of fungus. Coccomyces are a genus of foliicolous fungi, meaning that they colonize the leaves of vascular plants. Coccomyces dentatus can be found on the dead and decaying foliage of a number of other species including Gaultheria shallon, Arbutus menzeisii, other Berberis spp., Castanea spp., Quercus spp., and Rhododendron spp. among many others.

The black spots are hexagonally-shaped ascocarps made up of six triangular "flaps" that open upon maturity to allow the fertile spores within to be released. Richard has some close-up photos of this process. The borders that form the mosaic patterns occur where two mycelia contact each other and are sexually incompatible. The distribution of this species is widespread, although it appears to be most prominent in temperate zones. The staining and mosaic patterns vary greatly, this example being the most visually stunning that I have come across.

Feb 7, 2012: Peniophora rufa

Peniophora rufa

Today's photograph is courtesy of PietervH@Flickr (shared via the Botany Photo of the Day Flickr Pool | original image). Thank you!

Red tree brain fungus belongs to informal classification of fungi called the corticioid fungi or crust fungi. These fungi have effused fruiting bodies (flat and spreading), and are typically associated with decaying wood. For Peniophora rufa, the woody host species always belong to Populus, or the aspens and cottonwoods. Via Mycobank, Peniophora rufa is distributed in "North America, following the distribution of Populus tremuloides; Europe and Asia, following the distribution of Populus tremula".

Jan 4, 2012: Suillus paluster

Suillus paluster

Katherine is responsible for today's entry. She writes:

Many thanks to PietervH@Flickr for today's image of Suillus paluster.

Suillus paluster is commonly known as a red bog bolete, marsh bolete or swamp bolete, and is also scientifically known by these synonyms: Boletus paluster, Boletinellus paluster, Boletinus paluster, and Fuscoboletinus paluster. If searching for more information about it online, you'll get better results by searching for Fuscoboletinus paluster or Boletus paluster, as these names were in common use (and still persist) for many years. Suillus paluster was proposed in 1996, by Kretzer et al. in Internal Transcribed Spacer Sequences from 38 Recognized Species of Suillus sensu lato: Phylogenetic and Taxonomic Implications (Mycologia, 88(5): 776-785).

The caps of Suillus paluster are 2-7cm wide, broadly convex to plane or slightly depressed, and pale pinkish-purple to reddish-purple in colour. The pore surface is 1.5-3mm and pale yellow becoming more golden yellow and brownish with age, and does not turn blue when cut. The stalks are 2-5cm long and 3-7mm thick, and flesh is yellowish white to yellow in the cap, but reddish under the pileipellis and white in the stalk. Suillus paluster has a non-distinct odour and a mild or slightly acidic taste. Marsh bolete is found in sphagnum mosses under larch, throughout "eastern Canada south to Pennsylvania, west to Wisconsin". It is also associated with Pinus taiwanensis in Taiwan (PDF), and can additionally be found in China (Sichuan), Japan and the Republic of Karelia in Russia (where it grows in association with larch). Suillus paluster is edible, and fruits throughout August to November.

Nov 28, 2011: Morchella esculenta

Morchella esculenta

Work-study student Katherine is the author of today's entry. She writes:

Thank you Marianne (aka marcella2@Flickr) for today's photo of Morchella esculenta.

Morchella esculenta sensu lato, or in the broad sense, is distributed globally. However, the "species" is taxonomically confusing, as explained by Michael Kuo: "The short version of the story is: the name has been confusing since it was created; it has been applied uncritically for centuries; and, here in North America, we have at least four genetically distinct candidates for the name (which represents a European mushroom that can't be compared to our mushrooms until someone figures all of this out)" (Michael has also posted a longer version). The species was originally described from collections made in Eurasia, and since this photograph is from The Netherlands, it may indeed be the true species as originally published. Then again, perhaps not; in "Species diversity within the Morchella esculenta group (Ascomycota: Morchellaceae) in Germany and France", a 2004 paper by Kellner et al. (doi:10.1016/j.ode.2004.07.001), differences in the internal transcribed spacer (ITS) region within the nuclear ribosomal DNA (nrDNA) of 22 different samples of Morchella esculenta s.l., suggested the presence of three distinct species.

The Royal Botanic Gardens, Kew has a species profile for Morchella esculenta that makes mention of the taxonomic difficulties of the group, as well as a detailed description of the fruiting bodies and spore deposits.

Species of this genus in general are collectively referred to as the morels or sponge mushrooms. The name of the genus is derived from the old German word Morchell, a term meaning edible fungus or morel, and the species name from the Latin esculentus meaning edible, or good to eat. Unsurprisingly, Morchella esculenta, or the common morel, is considered one of the best edible fungi, and highly sought after by mushroom hunters. Fruiting bodies of Morchella esculenta are noted by the Royal Botanic Gardens, Kew as being "quite nutritious, containing high-quality protein, and being rich in minerals and low in calories". However, all sources I've read also note that they must be cooked prior to consumption! Uncooked morels are known to cause digestive upsets. Morels showing signs of decay should also be avoided, as they can be poisonous. David Arora in his book Mushrooms Demystified notes that one should always "split them length-wise to check for millipedes, slugs, and other critters that like to hide inside". Despite these issues, morels "[are] so esteemed in Europe that people used to set fire to their own forests in hopes of eliciting a bountiful morel crop the next spring!" Morels may also be preserved by being canned, frozen, or dried.

The Wikipedia entry on Morchella esculenta claims that this fungus species has also been used in Chinese traditional medicines for the treatment of "indigestion, excessive phlegm, and shortness of breath". Recent laboratory studies (in rodents) have shown "anti-tumour effects, immunoregulatory properties, fatigue resistance, and antiviral effects" and "antioxidant properties".

Nov 8, 2011: Cruentomycena viscidocruenta

Cruentomycena viscidocruenta

An entry compiled by Katherine; she writes:

Today, a brief entry along the lines of the recent run of autumn-coloured photographs, though it was taken during the Australian winter in late July. This photograph of the stunning red Cruentomycena viscidocruenta (Mycena viscidocruenta) is courtesy of Ken Beath (kjbeath@Flickr).

Commonly known as a ruby bonnet, Cruentomycena viscidocruenta is found in New Zealand and southern Australia (including New South Wales and Victoria). Via Discover Nature at James Cook University's article on Cruentomycena viscidocruenta, ruby bonnet has a cap that is 1-2cm in diameter, with the caps being convex when young and tending to flatten with maturity. The hollow stipe of ruby bonnet is up to 4cm long and 0.5cm wide. According to the Taranaki Educational Resource: Research, Analysis and Information Network (TERRAIN)'s article on ruby bonnet, "[Cruentomycena viscidocruenta] is usually found in small groups attached to small sticks and leaves especially in moist gullies in native forest, urban scrub and wood chip gardens".

As shown in Ken's photograph, Cruentomycena viscidocruenta is slimy when wet. The epithet viscidocruenta stems from the Latin viscos meaning "sticky" and the Latin cruent meaning "bleeding" or "bloody".

Additional photographs are available via New Zealand's Hidden Forest: Cruentomycena viscidocruenta, as well as a declaration on edibility ("No"). Mushroomobserver.org also has more photographs, along with a brief discussion on the possibility of using this species for dying clothes.

Sep 27, 2011: Pleurotus ostreatus

Pleurotus ostreatus

With today's entry, we welcome a new work-study student helping with Botany Photo of the Day, Katherine Van Dijk. Katherine is a fourth year student enrolled in the UBC's Environmental Sciences program. Katherine writes:

Thank you to mossgreen2011@Flickr for this picture of Pleurotus ostreatus.

Commonly known as an oyster mushroom, the name of this species comes from Latin: pleurotus meaning "sideways", and ostreatus relating to its similarity to the oyster bivalve (possibly its taste as well). This species is edible. First cultivated by Germany for sustenance during WWI, it is now cultivated world-wide. Due to its prevalent culinary uses, other names include píng gū in Chinese, nấm sò or nấm bào ngư in Vietnamese, and chippikkoon in Malayalam.

Wikipedia provides a fairly comprehensive description of the uses and prevalence of Pleurotus ostreatus, including its potential for lowering cholesterol, and its use in "mycoremediation", as termed by Paul Stamets.

Dr. Paul Stamets conducted an experiment with Dr. S. A. Thomas, whereby piles of soil contaminated with diesel are remediated using mycelia of oyster mushrooms. The results were compared to conventional remediation methods. A discussion of this study may be seen and heard in the TED Talks video "6 Ways Mushrooms Can Save the World" or Stamets' Fungi Perfecti site. The fungi act by breaking down the long chains of organic carbon from contaminants in the same way as they decay lignin and cellulose, their usual source of carbon.

Jun 9, 2011: Polyporus brumalis

Polyporus brumalis

Alexis Kho, Botany Photo of the Day summer work-study student, is again the author of today's entry. Alexis writes:

Jim Cornish@Flickr took this photo of Polyporus brumalis in Gander, Newfoundland, Canada. Thanks, Jim!

Polyporus brumalis is a fungus found in some parts of the Americas and Eurasia. This species is called winter polypore (brumalis meaing "of the winter") because it fruits in the wintertime in areas with mild temperate climates. In regions with colder, harsher winters, however, it will fruit in the spring and summer (see Schalkwijk-Barendsen's Mushrooms of Western Canada from 1991). The preferred substrate of winter polypore is the dead branches of hardwoods, especially birch trees. The mushroom caps of this species range in size from 1.5 to 10cm across, and have an inrolled margin and a depressed shape. Polyporus brumalis can be distinguished from similar looking species by the brown stalks of its mushrooms and the oval-shaped radially-arranged pores on the caps' undersides (Phillips' Mushrooms and Other Fungi of North America from 2005). Polyporus species in general are mostly leathery and woody in texture, making them inedible (via Miller's Mushrooms of North America).

May 20, 2011: Pleurocybella porrigens

Pleurocybella porrigens

A tip of the hat to Jim Cornish@Flickr for sharing today's photograph from last autumn in Newfoundland and Labrador (tops on my list of places yet to visit in North America).

Jim's photograph perfectly illustrates the English common name for this species of temperate forests in the northern hemisphere: angel wings. In the written accompaniment to his photograph on Flickr, Jim also explains the scientific name: "pleur meaning 'on the side' a reference to the stalk being on the side of the cap, cybella meaning 'small cap' and porrigens meaning 'sticking out'".

Pleurocybella porrigens is a wood-decay fungus associated with conifers (particularly Tsuga, the hemlocks), and more specifically, a white-rot fungus (in general, these digest lignin in wood and leave cellulose behind, though they can also digest both -- but lignin is less abundant, so it can give the appearance of leaving cellulose behind).

Important for some BPotD readers whenever a fungus is featured is the question of whether it is edible or not. For many years, the answer would have been "yes, but not particularly tasty". However, see: Savuc, P and Danel, V. 2006. New Syndromes in Mushroom Poisoning. Toxicological Reviews. 25(3):199-209. In this paper, the authors describe that in Japan a "convulsive encephalopathy outbreak was reported in patients with history of chronic renal failure" after ingestion of Pleurocybella porrigens (in Japan: sugihiratake). The question as to what caused the outbreak seems to have been answered: see Wakimoto, T et al. 2011. Proof of the Existence of an Unstable Amino Acid: Pleurocybellaziridine in Pleurocybella porrigens. Angewandte Chemie International Edition. 50(5) 1168. However, the why of the outbreak of poisonings remains unknown. Michael W. Beug explores that question in Pleurocybella porrigens toxin unmasked?, an article in McIlvainea: Journal of American Amateur Mycology.

Apr 28, 2011: Colus pusillus

Colus pusillus

Today's entry was written by Claire:

This vibrant photograph of the fungus Colus pusillus was taken by andrikkos (andrikkos_from_droushia@Flickr). Much thanks andrikkos! I was intrigued by the two other posted photographs from andrikkos as well: Colus pusillus 2 and Colus pusillus 3.

Belonging to Phallaceae, or the stinkhorn family, the fruiting bodies produce sticky masses of fetid smelling spores called gleba. The foul smell is intended to attract flies and other detritus-loving organisms that aid in dispersal when the sticky spores coat the insect's bodies. This particular fungus bears the common name craypot stinkhorn, and the visible fruiting parts, like others in Phallaceae, originate from an egg-shaped structure that emerges from the forest floor. Additional detailed pictures of this fungus are on Michael Kuo's MushroomExpert.com: Colus pusillus.

Colus pusillus bears its gleba on the pileus, the underside of the fragile receptaculum (the cage-like structure - on a common mushroom-type structure this would be the underside of the cap). Colus pusillus is thought to only occur in Australia but the few species described to this genus are widespread throughout the world. From Mycobank, here is the original description of Colus pusillus.

If you know more about this Australian fungus, please feel free to correct or comment!

Jan 7, 2011: Geastrum saccatum

Geastrum saccatum

Thanks once again to Robert Klips (Orthotrichum@Flickr) for sharing one of his photograph with BPotD (original via the BPotD Flickr Pool). Much appreciated!

Though these may appear to be acorns rapidly fired into small bits of cookie dough, they are actually the fruiting bodies of the rounded earthstar, Geastrum saccatum. Geastrum literally translates to earth star, and the genus has a cosmopolitan temperate and tropical distribution. Geastrum saccatum contributes to that broad range, as it is the most widespread species.

As Robert explains in his comments on Flickr, earthstars resemble puffballs when the fruiting bodies first begin to develop. As it matures, the outer skin (outer peridium) splits and peels back, forming the star pattern. In some species, the shape and length of the segments of the outer peridium are enough to elevate the inner spore sac away from the ground, but in the case of Geastrum saccatum, the fruiting body remains relatively flat and close to the ground (or as Michael Kuo describes in a linked article above, the spore case "sits directly on the arms, as though in a bowl (without a pedestal)".

Geastrum saccatum is a saprobe, gaining its nutrients from dead or decaying organic matter.

No, it's not edible.

Mar 11, 2008: Chytriomyces sp.

Chytriomyces sp.

The series for UBC Research Week continues. Today's write-up and photos are courtesy of Toko Mori. Toko writes:

My name is Toko Mori, a first-year graduate student in the Berbee Lab at the University of British Columbia. I study chytrid fungi, microscopic fungi that mainly live in freshwater. I especially focus on the local chytrids that parasitize freshwater microscopic algae. My long-term research goal is to create a tree of life of chytrids that parasitize algae and to see if there is any coevolutionary relationship between the species of parasitic chytrids and those of their host algae. I collected this chytrid on an alga, Vaucheria, from Burnaby Lake (Burnaby, BC) in August 2007. I have cultured it on agar and also co-cultured it with Vaucheria since then.

Since it seems that this is the first entry of chytrids in the Botany Photo of the Day, let me explain what they are. Chytrids are fungi, although they look quite different from mushrooms and molds, which we often think of as fungi. There are about one thousand species of chytrids which form the Phylum Chytridiomycota. Being the only group of fungi which reproduce by motile cells called zoospores (shown in picture 4), chytrids are considered to have diverged from the other fungi very early in their evolutionary history. Having motile spores gives them reproductive advantage in water. However, this is a double-edged sword; chytrids are unable to reproduce without moisture and thus bound to aquatic habitats.

Chytrids have recently attracted public attention as a cause for the population decline of amphibians. However, not all the chytrids are amphibian pathogens. To the contrary, many chytrid species are decomposers of organic matter in ponds and lakes, or parasites of microscopic invertebrates or algae, as in this case. Not much is known about their ecological roles.

Now let me explain these pictures. You are witnessing the moment of zoospore release, the highlight of their life history. The small round structure on the algal filament in picture 1 is a mature sporangium, where zoospores are produced. (The big bulge at the right end is a part of the alga, which I will explain later.) You can see the sporangium filled with small dots, each representing a zoospore. Five minutes later, the zoospores start to leave the sporangium, probably triggered by the sudden change in temperature caused by the intense light from the microscope. The change in pH of the surrounding water (when transferred from culture to a drop of distilled water on a slide) may also be the trigger. For a few minutes after the release, zoospores swarm just outside of the sporangium, until they start to swim away as in picture 3. As you may see in picture 4, the zoospores (ca. 4µm in diameter) have a flagellum like that of animal sperm. Eventually these zoospores stop swimming, retract their flagellum and encyst on a suitable substratum if they find one. Then they themselves will grow into a new sporangium, produce zoospores inside by mitosis, and start a new cycle of asexual reproduction.

A note for this alga. To co-culture this chytrid with its host, I received the culture of the host algal species, Vaucheria sessilis, from the Canadian Center for the Culture of Microorganisms at UBC. Vaucheria is unusual in that it lacks cell walls except when making reproductive structures; this entire filament seen here is one cell. The bulging end was formerly a spore, from which this algal filament grew.

Species identification is an important part of my research. Correct identification is the first step to making a tree of life. However, species identification of chytrids can be often difficult due to their simple body structure - there are not many morphological characters to study, at least on the light microscopy level. These days researchers combine molecular data and electron microscopy, together with traditional morphology. I have identified this chytrid down to the genus Chytriomyces, based on the light microscopic level morphology and molecular data.

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