Mystery Mushrooms

A cluster of mushrooms--almost like a bouquet--popped up in our front yard after a recent rain.  I have searched the internet trying to find out something about them, but I have come up almost empty handed.  They are certainly not the most showy mushrooms I have seen in the yard, no bright colors, only a slight golden tint in the sun.  They have no distinguishing features on the cap or stem.  Their main distinguishing feature is their size: the biggest is 5-6" (14cm) tall and about 7" (18cm)  in diameter.  I tried Googling "Large beige mushroom," "huge tan mushroom," "Big California Mushroom," but could not find a picture of them.

I checked the UC Berkeley mushroom guide and no luck there.  I learned from www.mykoweb.com that they are the Agaric type, which are the common 'gilled' mushrooms.  I looked at every picture in their Agaric list (see Here), but I could not find one that really looks like these.  I have no idea if these are poisonous or edible or hallucinogenic.  Maybe Tricholoma dryophilum?  Agaricus californicus? Pluteus petasatus?  Hebeloma sinapizans?  These are the closest matches I found, but none look quite right.  No wonder experts say that you should not gather wild mushrooms, unless you are an expert!

So if you are an expert mycologist, or if you recognize these and can give me their common or scientific name, I would greatly appreciate it.  Here is a little more information on them:  They grew out of a mulch pile left behind when we had a large eucalyptus tree removed about a year and a half ago. The stump grinder turned the roots and stump into a mound of good, rich mulch. These fungi appeared after about 3 days of rain in mid March, here in the east bay hills near Berkeley, California, USA.

Top View of Mystery Mushrooms

Golden Mushrooms in the Sun