Dog stinkhorn mushrooms (Mutinus caninus) growing on a woodland floor. These are the inedible fruiting bodies of this fungus, which feeds on decaying leaves in summer and late autumn. Dog stinkhorns develop from an egg-like object (sectioned at lower left). The growing white stalk ruptures the outer layer and raises a slime- covered head up to 12 centimetres above the ground to disperse the spores found in the black slime.