On Saturday, it rained off and on the whole day. The weather cleared late Saturday night or early Sunday morning. On Sunday, it was cold, the wind was blowing 10-15 mph, and there wasn’t a cloud in the sky.
On Sunday, I walked down the pond lily trail seeking shelter from the wind and listening for birds. Along the trail, there is a place where the Pacific Nine Bark shrub grows over the trail. At this spot, there is a bunch of lungwort lichen, Lobaria pulmonaria, growing. I was surprised to see that most of it had already dried out from the cold wind. When a lichen is dry, the fungus protects the photobiont layer from drying out, mainly a green alga in lungwort lichen. When a lichen is wet, the cells of the surface skin (cortex) of the fungus become more transparent. In this case, it exposes the vibrant green algal cells underneath. The green alga of the lungwort lichen, is able to perform photosynthesis to provide food.
Lichens do not have roots. They get their water and nutrients from their surrounding environment via air and rain, which is absorbed into the lichen's structure. Of course, this makes them susceptible to pollution, so only the most tolerant species grow in town.
Lichens are amazing organisms that come in a myriad of shapes and sizes. There are approximately 3,600 species of lichens in North America discovered so far. Look around, and you will quickly see a large diversity at the arboretum. Good luck!
Resources
About Lichens. https://www.fs.usda.gov/wildflowers/beauty/lichens/about.shtml. Accessed 30 Jan. 2023.
Lichen Biology. https://www.fs.usda.gov/wildflowers/beauty/lichens/biology.shtml. Accessed 30 Jan. 2023.
Lungwort. https://www.fs.usda.gov/wildflowers/plant-of-the-week/lobaria_pulmonaria.shtml. Accessed 30 Jan. 2023.
