Horse Mushroom

A number of a potentially poisonous white mushrooms are superficially similar but do not match all the key characteristics. For example, the poisonous Agaricus xanthodermus differs in that the cogwheel pattern on the veil is reduced or absent, the flesh within the stem base discolors to a bright yellow when cut, and the edges of the cap turn bright yellow when rubbed. The edible Agaricus silvicola is very similar in appearance. It differs in that the stem is more slender and it grows in forest habitats rather than in grass. It has been known to cause allergic reactions in some cases. The edible Agaricus crocodilinus differs in that the cogwheel pattern on the veil is reduced or absent and the cap is often scaled like the skin of crocodile rather than being fairly smooth.