A worldwide community photographing and learning about wildlife
Hygrocybe virginea
Hygrocybe virginea is a species of agaric (gilled mushroom) in the family Hygrophoraceae. It has been given the recommended English name of snowy waxcap in the UK. The species has a largely north temperate distribution, occurring in grassland in Europe and in woodland in North America and northern Asia, but is also known from Australia. It typically produces basidiocarps (fruit bodies) in the autumn. Wikipedia
Growing on moss along Crystal Springs Trail in Huddart County Park, Woodside, California.
Lacks the annulus and has broadly decurrent gills. I'm not certain with my ID but it looks likely.