Fields have eyes and every wood has ears.

Jews Ear fungi
The name comes from the story that Judas Iscariot hung himself from an elder tree, and this type of fungi is often found growing on elder trees.

Jews Ear is one of the few fungi which has the ability to withstand freezing temperatures. This is a useful attribute, since it develops new growths in January. It can actually freeze solid, and when thawed out shows no ill effects.