Lobaria

Lobaria is a genus of lichens that are common to cool, rainy areas, such as the Pacific Northwest, New England, parts of the British Isles, and New Zealand. They are foliose lichens, meaning that they grow in the form of leaves, almost always attached to the trunk of a large tree. Their common name is "lung lichens", due to their general shape, and a related belief that they could be used to cure lung ailments such as asthma. According to inaturalist.org, there are 14 species in the genus, with the most common being Tree Lungwort (Lobaria pulmonaria), with most of the species looking much alike, with small differences in coloring, texture and preferred habitat being the best way to distinguish them, most of which can only be done by experts.

Like all lichens, they are a symbiotic organism consisting of a fungus, which hosts colonies of a photosynthesizing green algae. Because of this,the surface of the lichen is a very bright green, especially in wet weather. Somewhat less commonly, in Lobaria, the fungus also hosts nitrogen-fixing bacteria, which means that Lobaria also help enrich the forest floor with nitrogen. They are also an important source of food for both macrofauna, such as deer, and also for microfauna, such as arthropods. In contrast to the green upper surface of the lichen, the underside, which hosts the bacteria, is a plainn white color.

I have also eaten them myself. After consulting works that said they were traditionally used as medicine, and finding no notice of toxicity, I decided to try to eat them. At first, only with nibbles. Despite their leafy appearance, that makes them look like lettuce, they are a fungi, and their texture and taste is closer to a mushroom. They are somewhat rubbery when wet, and crunchy while dry. They have an oddly salty flavor, and when dry, they resemble potato chips in both texture and flavor. I have also collected them and put them in stir fries. While so far, I have had no problems with eating them, I haven't tried to eat them in bulk, and eating too much at once might cause some type of gastrointestinal problems. Still, if ever lost in the woods, I think I could trust them for sustenance.