Botany Photo of the Day
In science, beauty. In beauty, science. Daily.

January 18, 2017: Botany Photo of the Day is being actively worked on. Returning soon!

Agaricus praeclaresquamosus

Agaricus praeclaresquamosus

This photograph is courtesy of “leafdesigner” (a member of the UBC Botanical Garden Forums) of Battle Ground, Washington. leafdesigner submitted this image via the BPotD Submissions Forum here. Thanks for the image, and also thanks for writing accompanying text! leafdesigner writes:

This mushroom with the mouthful of a scientific name is sometimes called the “western flat-top agaricus”. A member of the same genus as the cultivated or “button” mushroom, it is poisonous. The odor of crushed flesh is disagreeable, being described as “creosote-like” or “smelling of library paste”. A good field mark is the bright yellow staining that occurs when the base of the stem is nicked, although this also happens with the equally poisonous Agaricus xanthodermus.”

I'll add an additional link: Agaricus praeclaresquamosus via Mykoweb.

Botany resource link: the Fungus Identification Forum, recently separated out as its own discussion area on the garden's forums after a request from one of the forum members. Identification of fungi can be extremely challenging, often requiring the use of a microscope and “spore prints”. Unlike lichen identification, though, you don't need to walk around with a chemistry set (a story for another day). Despite often requiring lab work, identification to genus is possible for many fungi with a good image and description, like so: Hydnellum peckii (which I absolutely have to find one day for BPotD!).


Thanks for supplying the Mykoweb link- that's a good site. I might add that although Mykoweb says that this mushroom fruits in the mid to late winter, they are referring to California. In Oregon, Washington, and BC, it is to be expected in the fall.


hey kids, be carefull out there.
years ago i took up mycology, had all the field books,did all of the spore samples, i thought i had gotten pretty good.
i found this beautiful large mushroom,4"-5" inches across, it looked as though it came from market, the spores were gray-brown, it smelled wonderful! i sauted' it for dinner, i almost died, i turned white and cold, in a daze for several days, thinking that mabey i did die !
all the books tell you to very careful, thats an understatement.
i'll stick to morrels and puffers !!


Absolutely one should be careful before eating anything from the wild. Best advice if you want to eat wild mushrooms is to go with experienced collectors or join a mycological society. My primary interest in mushrooms is not gastronomical, however, but more aesthetic and, to a certain degree, scientific. There are many ways to appreciate wild mushrooms besides ingesting them.


Iam fairly new to the botanical world...interested in fungus and what do you mean Matt they're are other ways to appreciate wild mushrooms besides injesting them? I like the variety and the the visuals of the mushrooms, good photography!

What I mean is that you don't have to eat wild mushrooms to appreciate them. Some mushroom hunters are "pothunters," and they are primarily interested in mushrooms as wild delicacies. There is nothing wrong with this, as many wild fungi are exquisitely flavored. However, there are other ways to appreciate them: their beauty and their ecological role being foremost in my mind.


I'm in agreement with Matt re: beauty and ecological role.

Interesting to note that the key characteristic associated with Australian "Yellow Stainers" appears to be a rather lax ring. One of our local variants grows as large as a dinner plate and is ( for me) considered good eating. Unfortunately it is toxic to a very small number of people (I estimate one in 250 thousand) where it causes violent emesis. In 20 odd years of doing mushroom ID's for the local hospital system I have only encountered 2 cases of poisoning by Yellow Stainers. Our primary concern is Amanita phalloides and we've had some 15 poisonings and 2 deaths in that time despite a fairly directed public awareness campaign.. The last few years of drought have severely curtailed mushroom foraging.

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