Lichen Fruiting Bodies

In a previous post I remarked on the freezing and desiccation tolerance of lichens and mosses: Cold and Desiccation Tolerance of Mosses and Lichens. I illustrated lichens growing on the bark of our maple tree, apparently unfazed by a swing of temperature from a low of -17^oF on January 30, 2019 to a high of 56^oF on February 3, 2019.

Today it was raining and the temperature was 53^oF around noon, ideal conditions for lichen fruiting bodies (the reproductive structures of the fungal partner in the symbiotic association with the algae and/or cyanobacterium of the lichen) to form. Therefore I took a few higher resolution images of the lichens on the maple tree to capture this reproductive action:

Many lichens produce fruiting bodies (apothecia) that are typically flat, cup or saucer-shaped, often with a distinct margin. Others produce basidiocarps, some of which can be mushroom/toadstool shaped (see: Images of British Lichens: Lichen sexual fruiting bodies (ascocarps, basidiocarps)). Examples of both can be seen in the images above, although I cannot be certain about the exact species. The mushroom/toadstool in the first picture most likely represents a basidiocarp. The circular brown structures with a white margin in the third picture represent lichen apothecia.