(2010) April Mushroom of the Month
The Devil’s Urn, Urnula craterium
One of the first mushrooms to grow in the spring in Michigan’s hardwood forests is the Devil’s urn. Devil’s urns are easily overlooked because of their dark color that blends with the forest floor. This mushroom fruits from March through May and is a true harbinger of spring. Not long after the Devil’s urns start to fruit, we can begin to expect the first fruiting of the black morels. Sometimes all one sees of this mushroom is a black hole in the duff when the outer surface of the urn is covered with leaves.
The Devil’s urns are a saprobe (wood decayer) although the wood from which they are fruiting often is underground. They are a dark brown to black mushroom, club shaped before they open with a star-shaped pore and then shaped like a deep cup or urn. The fertile inner surface is also dark brown to black. The urns range from 1 inch to 2 ½ inches wide and are 1 ½ inches to 4 ½ inches tall. The margin of the opening is usually toothed or ragged as they expand to full size. The urns occasionally occur singly but usually in small groups or clusters.
The Devil’s urns are not poisonous but they are too leathery to consider eating them. There are a few other black urns but they do not occur in Michigan. One might mistake a Devil’s urn for a black trumpet but the different growing seasons early spring as opposed to mid-summer should easily distinguish them.
Last spring we collected samples of this mushroom for Tom Volk who
is conducting experiments on the medicinal properties of some of the
enzymes of this mushroom.