Lobaria

Lobaria linata is a large-lobed lichen with many ridges and hollows on its upper surface. It grows with mosses on the forest floor, at the bases of trees, and on the trunks of birch trees. It's bottom surface is a mottled brown and white.

During the dry parts of the year the lichens become very dry and crusty. They'll break rather than bend. As soon as there is precipitation and daytime temperatures above freezing, the lichens absorb moisture. Lobaria linata becomes a bright green and feels flexible to the touch.

Experiment: if the weather has been dry, find a small piece of this leaf lichen and put it in a freezer bag with some small dampened pieces of wood. Observe what happens.

If the weather has been wet and Lobaria linata is very green in its natural habitat, find a small piece and bring it inside. What happens to it in the drier indoor environment? What happens to it if you spray water on it?