When: 2007-09-10

Collection location: Menlo Park, San Mateo Co., California, USA [Click for map]

Who: Douglas Smith (douglas)

No specimen available

Unknown amanita here. I was able to put a gill section under the scope. The spores are amyloid, and the gill trama is divergent, so it is certainly an amanita. But it is a pretty funny one. Found growing in grass between two redwood trees. There are some pine trees about 50ft. away, and the other side of a paved path, but the redwoods were about 10ft away from this one.

This one actually matches a description in Arora, called ‘Amanita sp.’. So it was known as an unknown amanita in the area 20 years ago. Is there a better description of this today?

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Hey, great – thanks.
By: Douglas Smith (douglas)
2007-09-20 18:37:33 CEST (+0200)

This is great, thanks. Actually I found three more yesterday, and brought them along to the Fungus Fed. meeting in Santa Cruz, to see if anyone else knew about new info on these. No one really did… in fact there was a minor argument about then being Amanita, which I agree they don’t look much like. But I kept saying, amyloid spores, divergent gill trama, but that didn’t mean too much, plus I don’t trust myself yet on this stuff.

Anyway, I do have the three more here, and they spent 12 hours in the drier last night. I was going to use them for class on Monday, to get some practice in handling dried material in microscopic studies. I did find two more at the start of the week for Monday’s class, but they were pretty beat up. It looks like these don’t have a very long half-life in nature, they probably came up over the weekend, and were rotting by Monday.

I’ll keep an eye out for more examples of these, since I have now found 6 in the past two weeks here. But I’m going to talk to Dennis about the three I dried last night, if he wants them for the Theirs’ herbarium. If he wants them for here, then he has dibs on these samples. If not then I’ll send them along to you. And if I find more, I’ll dry them out and send them along.

You know, they do look a lot like that photo of A. singeri.

There is a provisional name for this species proposed by A.H. Smith.
By: R. E. Tulloss (ret)
2007-09-20 16:29:53 CEST (+0200)

Hello Doug,

Yes, this Amanita is an oddball. It is apparently not obligately mycorrhizal with woody plants. If it is mycorrhizal with anything, it has managed to evade detection in this arena…despite the best efforts of one of the bulldogs of west coast mycology—Jan Lindgren.

A.H. Smith proposed to name this species (many years ago) “Amanita pruittii.” The honor was to be bestowed on an extraordinary naturalist who was a collector corresponding with Smith from Oregon. It is said that Pruitt was so gentle and quite that he could call birds down from the air.

Jan Lindgren (with help of people who knew Pruitt) rediscovered the story of Pruitt and identified the original collection site…a field that is mowed and occasionally burned to preserve its ecological status. Originally the field was planted in Sorghum, but modern conservation practices have returned the field to native grasses and other (mostly?) native plants. After a burn, A. pruittii has produced extra large fruiting bodies in the conserved field.

The closest relative (according to preliminary molecular work) is A. singeri Bas of southern Europe. Both belong in Amanita subsect. Vittadiniae Bas, which seems to be almost entirely composed of taxa with doubtful mycorrhizal relationships. They are, for example, species of the S. American pampas and the Russian Steppes…as well as North American high prairie and high elevation desert. Most are not commonly collected. However, Amanita thiersii Bas is spreading in N. America (from what we can tell from incomplete records) and has become rather common from central Mexico to Illinois. Amanita nauseosa (Wakef.) D.A. Reid is fairly common along the Gulf Coast of the US (and probably Mexico). Both of the latter are lawn mushrooms in parts of the southeastern US.

For more about these taxa, you can check out the web pages that can be accessed from the alphabetic list of taxa in Amanita sect. Lepidella. Amanita pruittii isn’t published and doesn’t have its own web page yet; however, try such species such as those listed above (singeri, thiersii, nauseosa) as well as the type of the subsection — A. vittadinii.

These pages will give you links to other pages of species in the subsect. If you’d like some characters to compare with your data let me know. I have good spore size and shape data for example.

If you find this critter again, I’d love to have a Stanford campus specimen to include in the protolog. These guys pick up a lot of water from the air after being dried (I refer to the whole subsection), so get it really crispy before you take it off the dryer.

Very best,