Lichens have best been described to me as a fungus that took up farming. They consist of an alga or cyanobacterium (“blue-green alga”). Lichens are traditionally described as a mutualistic symbiosis but in reality more like a controlled parasitism. Even so, each partner seems to benefit. The algal or cyanobacterial partners provide food, vitamins, and amino acids to the fungus, while the fungal partner provides a form of protection.
Scientists wondered why some lichens that genetically test as the same can look different. To make things more complicated, recent research has now indicated that lichens can sometimes be more than two partners! The third partner comes from a separate phylum of fungus. It is now hypothesized that this third partner, yeast, protects the organisms, like through the production of secondary metabolites that acts as defense compounds.
Want to learn more about lichens? The Ohio Moss & Lichen Association (OMLA) has a great Lichenology 101 page to check out.
To learn more about specific lichens you can find in West Virginia and Central Appalachia, a guide on lichens as ecological indicators of habitat types can be viewed below. While not a comprehensive species guide, it’s a great way to get started with recognizing lichen characteristics while out in the field.FRANTZETALLICHENGUIDE_272020