Though the fossil record for early fungi is scanty, fungi have been on Earth for at least 350 million years and perhaps much, much longer. Historically considered plants, fungi are now known to share traits with both plants and animals but to actually be their own lineage. Incredibly important in the environment for their ability to decompose organic matter and release carbon and other elements, fungi are everywhere in large numbers—including in the soil, in the air, in water bodies, and in and on the bodies of plants, animals, and humans. The Garden’s fungal research focuses primarily on the Agaricales and the Boletales (mushrooms, puffballs, and related groups).
Lichens are not exactly plants, either. As one lichenologist has described them: “Lichens are fungi that have discovered agriculture.” Living as a composite organism in a symbiotic relationship, lichens are composed of a fungus and either an alga or a cyanobacterium. The fungus provides shelter from extreme conditions for the alga or cyanobacterium, while the alga or cyanobacterium—both of which are photosynthetic—provides sugars for the fungus to feed on. These amazing symbiotic organisms are also able to shut down metabolically when conditions are unfavorable and are often the first colonizers in some of the harshest places on Earth. Lichens have been around for more than 300 million years.