Thursday, June 24, 2010

Why join your local Mycological Association?

Some weeks ago I went for the first time to the Mycological Association of Washington (MAW) monthly meeting at the Chevy Chase Public Library (it is usually there and at the first Tuesday of each month, but you feel like going please check on first to make sure they haven't changed the venue). The meeting usually starts at 7 pm and it is a great opportunity to learn more about mushrooms, get to know other mycophiles from all ages and experience levels, and learn about all the mushroom related activities in the surroundings. Every meeting people take their recent findings, either to get an educated opinion about identification, or just for the sake of showing off to other people. On the last meeting there were a huge variety of mushroms, including jelly ears (Auricularia auricula), meadow mushrooms (A. campestris), reishi mushrooms (Ganoderma lucidum), Boletus fraternus, Thick Maze Oak Polypore (Daedaleopsis quercina) and a large variety of unidentified mushrooms.

In many ways, the meeting reminded me of the Bambui (a very nice Spelunking group in my hometown) meetings I used to go. The format is a little bit more formal, but still informal enough to make it enjoyable. The current president (Ray LaSala) makes sure everything that needs to be reported gets reported. Also, there was a section on mushroom identification by one of the former presidents, which displayed most of the field guide available and discussed the pros and cons of each one (really useful information). Last, there was a slide section with hundreds of mushroom images with nice commentary by a former president of MAW and time for questions. Really good stuff!

Saturday, June 19, 2010

A "stinky" Russula

I have found these Russulas growing on mulch and grass  in my block over the last month. To me, they are not very nice looking mushrooms and, every time I found them, they were braking apart or destroyed by the lawn mowers. Last week I found some clusters that were in good shape and decided to take some home to see if I could determine their identity. On a closer look, the characteristics that stand out on these mushrooms are the strange spermatic smell, the yellow cuticle, and the compressed (shaped like a compressed tube) wide white stipe (stem). Unfortunately, when I collected this mushroom I did not know how difficult it is to identify Russulas and, therefore, did not pay enough attention to some of the important details for this hard task (spore shape and size, cap cuticle separability etc). Indeed, there are many identification keys around the internet, and each one is a little bit more confusing then the other. While searching for information on how to identify my specimens I came across a nice webtool for North American Russulas identification on the Museo Tridentino de Scienze Naturali website, which I highly recommend. Other options are the Pacific Northwest Key Council website (which by the way is a great place for getting identification keys for all North American mushrooms). Last, for specific information on stinky Russulas, there is the key key.

Location: Rockville, MD
Habitat: Gregarious, growing on grass, under conifers

Pileus diameter - 42 x 54 mm | 46 x 48 mm
Pileus height - 22 mm | 15 mm
Stipe length - 40 mm | 43 mm
Stipe diameter at apex - 13 x 15 mm | 13 x 12 mm

Stipe diameter at middle - 13 x 20 mm | 13 x 16 mm
Stipe diameter at base - 13 x 20 mm | 15.5 17.5 mm

Pileus - Yellow/brown, dry, glabrose, cracking, smooth, convex on young specimens and becoming depressed on older ones, round, margin inrolled on young speciments and upturned in older ones, flesh is white, brittle, smell is spermatic
Hymenium - white, gilled, gills are crowded/close, smooth, adnate
Stipe - white, compressed, varying from equal to clavate, hollow with floccose contents, inserted, with brown stain at the base

This looks like a member of the foetid Russula family, possibly R. foetens. Nevertheless, identifying Russulas is not an easy task and, given my naivete when collecting data on this mushroom, I had a hard time identifying it. Some possibilities would be R. amoenolens (a common foetid Russula in North America) which has been described to appear in the region where I live, but the "spermatic" smell seems to be a characteristic of R. foetens (hence the latin name foetens, which means stinky). Many of the characteristics of the mushroom also match R. laurocerasi, R. foentetula, R. and fragrantissima. For now, I'll have to classify it only as Russula sp.

Saturday, June 12, 2010

Amanita volvata?

This morning I went on a foray organized by the Mycological Association of Washington at the Rock Creek Park in Washington, DC. The park is a great place for finding mushrooms and the foray was very agreeable. It rained a lot this last week and therefore there were many mushrooms growing, specially slime molds and polypores. Some of the specimens I remember were the long Xerula furfuracea,  the buggy Megacollybia platyphylla, White Coral Slime (Ceratiomyxa fruticulosa),  Stalked Scarlet Cup (Sarcoscypha occidentalis), Red Raspberry Slime (Tubifera ferruginosa), Turkey Tail (Trametes versicolor), Artist's Conk (Ganoderma applanatum), Coal Mushroom (Daldinia concentrica) and a nice cluster of three amanita mushrooms that we thought could be American Amidella (Amanita volvata) and which I decided to bring home to analyze more carefully (I brought home only one and I chose the intermediate sized one, which I used for the description below). 
As all Amanitas, this one had a volva (sac of tissue around the stem base), but contrary to most of them, this one did not have a ring around the stem. Mycologists use this information to help classify mushrooms, and since most amanitas are lethally toxic when eaten (with as small number of exceptions), one should pay a lot of attention to every detail when trying to identify amanitas, specially the presence or absence of rings and volvas. Other things that we noted immediately on these mushrooms was the large size (the biggest one had a cap that was probably 15 cm wide or wider) and the white color. On a more careful examination we observed that the mushroom bruised red/pink and that the gills under the cap were white. All these characteristics (and the ones described below) could suggest a member of the Amanita section Amidella.

After posting my photos and description at Mushroom Observer,  Dr. Rodham Tuloss (an Amanita mycologist which has a very good website on Amanitas) sent me some comments and pointed out that "Amidellas are very hard to determine from a picture or even with one in your hand" and that ones has to rely on a microscope. Therefore for now I'll call this specimen just Amanita sp.

If this mushroom were indeed A. volvata, it would be a non-edible mushroom (as most Amanitas). 

Growing on soil, near dead wood, gregarious, cluster of two specimens very close to each other and another approximately 50 cm away.

Pileus – white, dull, dry, with remnants of the universal veil (appressed scales), bruises initially light red and then becomes brown very slowly, round, convex to flat, flesh is white, margin is striated.
Hymenium – gilled, gills are white, crowded, free, smooth, margin is entire, crenate.
Stipe – white, hollow with cottony cluster inside, cartilaginous, tapered toward apex, with white and elongated volva at the base, flocose near apex, inserted, smell is weak and non-distinctive.

Pileus height – 22 mm
Pileus diameter – 48-50 mm
Stipe diameter at apex – 8 mm
Stipe diameter at middle – 9.5 mm
Stipe diameter at base – 13 mm
Stipe length – 120 mm
Volva height – 4.5 cm

Monday, June 7, 2010

An edible Amanita that I'll not eat

This is the second mushroom I found on my walk today. The shiny silver metallic cap caught my attention. When I moved the grass aside to see the base of it, to my surprise I found a bright white volva and a white stem, therefore suggesting a mushroom from the Amanita genus.

Date: 06/07/2010
Location: Rockville, MD
Habitat: growing on grass, two specimens close together

Pileus diameter - 30 mm
Pileus height - 21 mm
Stipe length - 70 mm
Stipe diameter at apex - 6.7 mm
Stipe diameter at middle - 6.7 mm
Stipe diameter at base - 6.7 mm

Pileus - metallic gray, glabrous, round, convex, margin entire, striated, flesh is white, does not bruise any color, smell is non-distinctive
Hymenium - white, gilled, gills are close, free, narrow, smooth/finely serrulated
Stipe - white, central, somewhat compressed, hollow, equal, with white volva, no ring, flexible, inserted
Spore print - white

This looks like Amanita vaginata, one of the few edible amanitas. The white spore print, the presence of a white volva, metallic gray cuticle, absence of a ring and the white free gills are all very suggestive of this species. Despite the reasonably easy identification I am not brave enough to eat it and would not suggest anyone eating it. Amanitas cannot be taken lightly and a single mistake is often fatal (causing a painful and long death due to liver insufficiency which is only treatable by liver transplantation). Unless you are 100% sure of the identification, you should never ever eat amanitas (unless it is a cultivated species and you are buying it from a reliable commercial vendor). The other famous edible amanita is A. cesarea (Cesar's amanita) which is also reasonably easy to identify, but which also requires the utmost care.

Another bolete

It is amazing the variety of mushrooms one can find just walking around the block, specially if you consider that I live in a highly urbanized area that does not have much more than lawn, pines, oak and maple. Everyday I go out I see at least two or three different mushrooms which I had never seen before. Today I found two nice specimens: a bolete and a silver color gilled mushroom which I'll decribe later.

Date: 06/07/2010
Location: Rockville, MD

Pileus diameter - 32 mm
Pileus height - 22 mm
Stipe length - 45 mm
Stipe diameter at apex - 10 mm
Stipe diameter at middle - 10 mm
Stipe diameter at base - 10.5 mm

Pileus - dark brown, dry, dull, convex, round, glabrous, margin is entire, no partial veil, smell is agreeable but non-distinctive, insipid. Flesh is white and bruise blue quickly.
Hymenium - with pores, red/brown, bruises black (it may be very dark blue), pores are small/medium, tubes are 6.9 mm at thickest part of hymenium
Stipe - solid, brown color outside, clavate, inserted, no ring or volva, bruises black inside when cut, it is red colored towards the base (inside), flexible, no reticulation, no scabbers.
Spore print - could not obtained

This is a bolete but I could not identify with certainty the species. It is possibly B. subvelutipes but I would need to check the spores and the microscopic characteristics of it to be certain. Anyway, since this bolete has a red pore surface and bruises black I would not eat it. There is a good chance it is poisonous since most boletes with red pores are.

Sunday, June 6, 2010

Boletus sp.

It rained a lot this week. Therefore there are plenty of mushrooms growing on the lawns around my block. On a short walk today I spotted at least 5 or 6 different species of mushrooms growing (ex. Russula sp., Ganoderma lucidum, Panaelous fonisecii and some two or three others that I did not know). I am going to start by these boletes which I though were quite beautiful.

Date: 06/06/2010
Location: Rockville, MD
Habitat: Growing on grass, two specimens one meter apart

Pileus diameter - 25 mm | 26 mm
Pileus height - 5.5 mm | 8.8 mm
Stipe length - 31 mm | 31 mm
Stipe diamater at apex - 6.8 mm | 8.8 mm
Stipe diameter at middle - 7.6 mm | 10.2 mm
Stipe diameter at base - 10.2 mm | 8.5 mm

Pileus - Brick red/orange brown color, glabrose, dry, dull, smooth, round, convex/flat, margin is entire,  plane, no partial veil, insipid, inodorous.
Hymenium - white with tiny pores, bruises brown but very slowly, pores are circular.
Stipe - solid (one of them had a small central whole towards the middle of the stipe), white flesh, bicolorous surface with brown bottom and light brown top, inserted, no ring, volva or reticulation.
Spore print - did not manage to obtain one.

It looks like a bolete but I can not identify the species. I posted it on Mushroom Observer to see what other people thing and Irene Anderson suggested that it could be Gyroporus castaneus. This little bolete is a common urban inhabitant. Roger's Mushrooms consider it to be edible and excellent. Given that boletes are reasonably easy to identify and, if you exclude the red boletes and the ones that bruise blues, most do not have any poison next time I find other G. castaneus I'll definitely try them ;-)

Train Wrecker

Yesterday, at the playground with my daughter, I spotted this one growing under a pine tree. The big and white cluster shined against the grass and the pine trunk making it easy to spot from the distance. This made me wonder about how easy it is to find plenty of mushrooms even on a highly urbanized area like the one where I live.

Location: Rockville, MD
Date: 05/10/2010
Habitat: Cluster of three specimens, growing under live pine, caespitose (3 specimens connected through the stipe in the shape of a trident).

Pileus diameter - 35 mm | 70 mm | 80 mm
Pileus height - 10 mm | 17 mm | 18 mm
Stipe length - 35 mm | 43 mm | 41 mm
Stipe diameter at apex - 7.5 mm | 10.5 mm | 13.5 mm
Stipe diameter at middle - 6.0 mm | 9.5 mm | 12.5 mm
Stipe diameter at base - 5.7 mm | 11.5 mm | 10.0 mm

Pileus - light cream color with brown, concentric scales looking like remnants of the universal veil, scales can be detached with a little effort, cuticle is dull, dry. Shape is round, convex to flat, narrowly depressed. Margin is inrolled, tinted light yellow, somewhat eroded. Smell is fragrant but non-distinctive. Flesh is white.

Hymenium - gilled, gills are white, attached and sub-decurrent, subdistant, moderately broad, somewhat eroded.

Stipe - central, solid, flexible, radicated, equal, scabrous. Flesh is white, does not bruise any color upon cutting, when young surface seems fibrilose.

Spore print - white

This is very probably a specimen of Neolentinus lepideus (previously named Lentinus lepideus), which has the common name of Train Wrecker. Another option would be that this is a Neolentinus ponderosus (the appressed scales on the pileus are suggestive of this second species). See a key for this genus here. Roger Mushrooms and Miller's Mushrooms of North America consider N. lepideus edible1,2 while Kuo consider it mediocre3 (Although the smell is quite good, I haven't tried it and do not plan to try it). The Falcon guide mentions that it is quite tough and that it requires considerable cooking to soften them enough to eat, therefore suggesting that only young specimens are good and that the caps are more appropriate for consumption than the stipes.

On another note, almost all the observed characteristics described above fit the descriptions for this fungi. The only thing that is a bit strange to me is that no guide I have mention that it has a radicated stipe (see the root like structure on the photos). Maybe the other authors did not dig their specimens but I doubt it. Alternatively, this is a new species of Neolentinus (because of the radicated stipe I would possibly call it Neolentinus radicatus ;-). For now, I'll freeze it and extract some gDNA out of it, just in case.

Last, the common name for this mushroom is derived from the fact that it is usually found growing on wood and in some cases in railroad ties, supposedly being able to cause a train wreck by damaging the tracks. This fungi is saprotrophic and causes a wet rot in construction materials and, according to the wikipedia, it is highly resistant to wood preservatives (i.e. creosote and others). I am sure you don't want to eat mushrooms growing on treated wood, specially because in the past some people used to treat wood with heavy metals and some nasty non-biodegradable organic compounds ;-).

1 - Rogers Mushrooms. Retrieved on 06/05/2010.
2 - A Falcon Guide to North American Mushrooms (2006). Miller Jr. OKM and Miller HH. First Edition. Globe Pequot Press, Guilford, CT. ISBN 978-0-7627-3109-1.
3 - 100 Edible Mushrooms with tested recipes (2007). Michael Kuo. University of Michigan Press, Ann Arbor. ISBN-10: 0-472-03126-0.