Monday, June 3, 2013

First Monday Mushroom: Lichen Agaric

This month we have an example of how topsy turvy taxonomy can be.Our mushroom is a small, moist, light brown-fading to yellow capped mushroom, with cream-yellow gills descending onto a light brownish stalk. The mushroom is found growing alongside lichens.

Lichen Agaric Lichenomphalia umbellifera
The reason this mushroom is an example how taxonomy can be rough in the fungi kingdom is all in the name. The Lichen agaric was once named among the Omphalina mushrooms. These mushrooms were given this name because of their small size and belly button like central dimple. This linked them to an older mushroom genus called Omphalia.; which was deemed as an illegitimate later homonym.  This means that several species which were categorized as Omphalina and Omphalia based on appearance had to be renamed because they did not truly belong there. The lichen agaric, once named Omphalina ericetorum, was one such mushroom. Its new and rightful name became Lichenomphalia umbellifera.

The key I am using is the  National Audubon Society Field Guide to North American Mushrooms and was published in 1985. Due to its publication date this key only gives the outdated name, but by cross referencing to newer keys and mushroom resources the history and newer identification becomes readily available.

National Audubon Society Field Guide to North American Mushrooms

 (Key C)
Key to small, fragile mushrooms with caps less than 2 inches across and slender stalks.

1.            Mushroom on cones of conifers or on fallen magnolia fruits – 2

1.            Mushroom not as above – 3

3.            Mushroom growing on other mushrooms – 4
3.            Mushroom not as above – 5

5.            Mushroom growing on moss – 6
5.            Habitat otherwise – 9

9.            Mushroom growing with lichen – Omphalina ericetorum (Lichenomphalia umbellifera)

9.            Mushroom not growing with lichen -- 10

Photo cred: James Lindsey at Ecology of Commanster [CC-BY-SA-2.5 ( or CC-BY-SA-3.0 (], via Wikimedia Commons