White Mushroom with white gills and bulbous base

[Rondayvous]

I found a bunch of these around the drip line of a Cedar tree. Nothing noteworthy about the smell.

 leucoagaricus leucothites? 

[bobby b]

Looks like it. Last year was the first year I saw it.

[Dave W]

Lack of ornamentation on the stipe base, smooth cap surface, and ring on the stalk that looks like it may be partially detachable all point toward L. leucothites. Of course, the problem here is potential confusion with genus Amanita. 

I have eaten L. leucothites, and found it to be of good quality. But, I still find it kinda spooky gathering this for the table, and generally I pass on using them. The dextrinoid spores are a good diagnostic factor (although virtually mushroom species housed in Leucoagaricus, Leucopcoprinus, Leucocoprinus, Lepiota, Chlorophyllum, and Macrolepiota... ie. the former Lepiotas... have dextrinoid spores). Unfortunately, you need Meltzer's reagent to test spores for dextrinoid (or amyloid) reaction. 

[Rondayvous]

Since many mushrooms deaths are from mushrooms that look like this, it is a firm pass in my book.

You also started me down the rabbit hole of Meltzer's reagent.

Melzer.pdf

[Dave W]

Yeah, the ingredient Chloral hydrate is a controlled substance. You used to be able to get Meltzer's on the international market, through the mail. There were companies willing to send it... Germany, England, China. Some folks have luck getting it via a prescription written by an MD. My doctor said he do this, but I could not find a pharmacy willing to fill it! I still have some obtained awhile back. I use this syringe-type device to mete out the tiniest useful amount. Luckily, Meltzer's has decent shelf-life. I have heard there's a compounding pharmacy in Maine that will fill a script. 

[JOHNY]

Have you tried Logol's solution?

Might be easier to get because it does not contain Chloral Hydrate

[Dave W]

Here's a paper on amyloid/dextrinoid reactions using Meltzer's, Lugol's, or just plain iodine.  https://namyco.org/docs/Melzer__Lugo.pdf   I see there's a photo showing a "dextrinoid" reaction with Lugol's applied to Amanita frostiana spores. Champignons du Quebec says A. frostiana in non-reactive in Meltzer's. I have tested spores of A. frostiana (as it looks a lot like A. flavoconia, which has amyloid spores). I have not ever noticed a dextrinoid reaction with A. frostiana spores in Meltzer's. So, I suspect there are possibly false-positive results associated with Lugol's. In the example being considered here --Leucoagaricus vs. Amanita-- this would be a critical distinction. 

[Tracy Montague-Fryer]

How would you tell the difference between leuco.- and aminata? I mean, look at the size of this thing!  16cm across. Practically a steak. Found in Cape Town South Africa autumn, under a tree in a mixed ecology (acacia, white oak amd others). Stem is not hollow.  Cap is smooth and dry, but was slightly glaucous on one edge. When bruised, yellows slightly. No unusual detectable smell.

[Kevin Hoover]

Dave,

Ask around the Eastern PA club. If I recall correctly, one of them was able to get a pharmacy in Chambersburg to fill their prescription 

[Dave W]

Based upon the shape of the ring (looking a bit like a short tube collapsed onto the stalk) I think Tracy's mushroom is Leucoagaricus. But, a key trait is missing, namely the undamaged stalk base. For an amanita mushroom there would be some sort of basal volva, ie. remains of a universal veil. It doesn't look like this is the case with Tracy's mushroom. But, I would never want to risk misidentifying what may be a deadly poisonous mushroom. 

Thanks for the suggestion, Kevin. A friend got some Melzer's for me over a year ago; maybe a little more than one ounce. I use a tool that looks like a syringe to uptake the tiniest useful amount. After over a year, I still have over half left. And I use it fairly often.