arbuscular mycorrhizal (light green) are most common in the grasslands and croplands of Virginia, while ectomycorrhizal fungi are found on the forested ridges
Source: Society for the Protection of Underground Networks (SPUN), Underground Atlas
Fungi appeared on Earth at least a billion years ago as one of the earliest forms of life, and have followed a unique evolutionary path. They developed a nucleus within the cell, but create cell walls with chitin rather than the cellulose used in the plant kingdom, or membranes with cholesterol used in the animal kingdom.
Fungi develop multicellular structures, filaments known as mycelium with individual cells called hyphae. New cells grow at the tip of a filament, and the soil throughout Virginia is filled with fungal tissue that is "out of sight, out of mind" for most people. Mushrooms appear above the surface. Those obvious features serve to produce and distribute spores.1
Mushrooms can be tasty such as chanterelles (Cantharellus sp.) and Chicken of the Woods (Laetiporus sulphureus and Laetiporus cincinnatus), or poisonous such as the Destroying Angel (Amanita bisporigera). "Magic mushrooms" that cause people to hallucinate when ingested due to psilocybin remain illegal in Virginia.2
In the natural environment, fungal cells interact with plants to exchange water, minerals, carbon, and other material. The symbiotic relationship developed 475 million years ago when plants began to grow on land.
In grasslands and croplands, fungi typically intrude into plant cells and grow tree-like structures ("arbuscules") within them to mediate the exchange of fluids and nutrients. In forested areas, ectomycorrhizal fungi grow around the tips of plant roots rather than into the cells. The exchange of materials occurs within a "sleeve" of hyphae surrounding plant cells at the tip of the roots.3
The diversity of fungi is poorly understood. Scientists are just starting to identify where fungal biodiversity is rich and where rare forms justify government action to protect a valuable genome. Studies are also revealing how the mycelium network that forms a "wood wide web" in forested areas can transfer nutrients among individual plants and between species. The rare species of fungus appear to be located in areas with extreme climates, such as the tops of mountains.
In 2025 researchers identified gaps between the locations of rare fungi and areas protected against disturbance:4
arbuscular mycorrhizal (light green) are most common in the grasslands and croplands of Virginia, while ectomycorrhizal fungi are found on the forested ridges
Source: Society for the Protection of Underground Networks (SPUN), Underground Atlas