agaricus arvensis(n = noun.plant) horse mushroom - coarse edible mushroom with a hollow stem and a broad white cap;
is a kind of agaric
is a member of agaricus, genus agaricus

acinos arvensis, agaricus, agaricus campestris, alauda arvensis, anagallis arvensis, anthemis arvensis, bromus arvensis, convolvulus arvensis, genus agaricus, mentha arvensis, scabiosa arvensis, sinapis arvensis, spergula arvensis, veronica arvensis, viola arvensis