ID for agaricus?

[Fungus Amongus]

Hey all! This is my first post on the boards. I'm an avid mushroom hunter from Berkeley,CA. I was out hunting in Point Reyes yesterday and stumbled upon some interesting agaricus. They smell like anise seed and gradually stain yellow,but are too thin stalked to be horse mushrooms? I found them in mixed hardwood forest fruiting under a bunch of madrone leaf litter. If anyone has any ideas as to the species do tell. I think they could be Agaricus Silvicola but I might be wrong!!

[Auspicion]

I think that agaricus silvicola has darker gills than this specimen when mature. Do a little more research.... I would be weary because those also look like the oh-so-common amanita phalloides. Personally, I would be looking in the amanita family just because it seems to have both a volva and an annulus. Did it have a membranous film around the base?

[Dave W]

Three genera of mushrooms that are easily confused are Agaricus, Amanita, and Leucoagaricus. A brown spore print immediately points toward Agaricus. (There are also some brown-spored mushrooms that may be confused with Agaricus... for example, some types of Agrocybe.) White print points toward Amanita or Leucoagaricus. A very useful trait for distinguishing between Amanita and Leucoagaricus is the base of the stalk. Amanitas generally exhibit a basal volva structure that represents the remnants of a universal veil... a covering over the entire newly-emerged Amanita button. Leucoagaricus leucothites (= L. naucinus) has no universal veil and consequently no basal volva.

I mention all of this about the stalk base because the mushrooms seen in the photos above appear to have been cut off above the very bottom of the stalk. When collecting for the purpose of identification, you should try to preserve as many traits as possible.

Also, the photos appear to have been taken indoors. Outdoor photos taken in shade or filtered sunlight are apt to best portray the subtle colors of a collection. I'm having trouble deciding if the gills in this collection are white, off-white, pale gray, or pale pink.

My guess is these are either Agaricus or Leucoagaricus. Gill color can be tricky with these two genera. Agaricus have gills that turn brown, but some species have very pale gray (or slightly pinkish) gill color at first. Leucoagaricus have white gills, but the gill color in older specimens may turn a bit on the pink/tan side. Leucoagaricus have white spore prints, but if a very thick print is allowed to sit out for an extended period, the print may begin to look a bit pinkish. Agaricus spore prints are unmistakably dark brown. Some Agaricus and some Leucoagaricus species are sickeners.

Finally, as Auspicion points out above, if here is even a tiny chance that a mushroom represents one of the white/pale Amanitas with annulus, then do not eat it, as it may be DEADLY poisonous. Many of the hundreds of Amanita species are poisonous.

[Dave W]

Also... Fungus Amongus, your location is listed as "United Sates". More specific location inf would be helpful. For instance, many of the mushrooms that routinely appear in western North America never appear in eastern NA, and vice versa.

[Fungus Amongus]

Thanks for all the input guys! I don't think they are A. Phalloides or any Amanita for that matter as they lacked the volva at the base of the stalk when I found them. Dave, as far as gill color goes, they are almost a grayish-pink but the specimens also aren't very old yet. Also their anise-like odor is very pronounced, are there any species of Leucoagaricus that have an odor like that?

Also I'm located in Berkeley, CA and the mushrooms I found were in Pt. Reyes just up the coast a little ways.

[Dave W]

There are species of Agaricus that occur in western NA but do not occur in eastern NA, such as the toxic A. californicus. Pale gray/pink gill color on young specimens points toward Agaricus. Here in eastern NA, A. arvensis types often have pale gray gills at first, and A. abruptibulbus has very pale (almost white) pinkish gills at first. The pleasant almond/anise odor often indicates the species is edible. Here in the east, the ones that sicken generally have an unpleasant phenol odor that may be slight. Some people apparently don't readily detect this odor. I don't know if the odor criterion holds for western NA types.

To be certain of the genus, I suggest using a mature specimen for a spore print. Sometimes an immature mushroom that has been harvested may be allowed to mature by replanting it outside in an appropriate environment. Or you may be able to entice a cap to open by propping it up while the stalk base makes contact with a damp sponge.