When I was doing my Ph.D., I spent many hours looking at peat cores. This meant looking down a microscope and sifting through half-decomposed plant remains, trying to figure out what kind of vegetation used to grow in the site that the core had come from.
Many plants that you find in peat cores are mosses, and while they can be tricky to identify, they are often very beautiful if you look at them up-close. For my next drawing, I decided to pick a structure that I very rarely encountered in my peat-core years: a peristome – the ring of teeth that surrounds the opening of the capsule in many mosses.
The peristome helps to protect and disperse the spores that develop in the capsule. The teeth will often move in response to changes in moisture, which is a fun thing to have students try out and observe in an introductory bio lab.