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 -17oF on January 30, 2019 to a high of 56oF on February 3, 2019.
Today it was raining and the temperature was 53oF 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.