Laccaria bicolor, often called the Bicolored Deceiver, is a common mushroom found across temperate regions of the world, including North America and Europe. This species is recognized by its distinctive appearance, notably its combination of earthy cap colors and contrasting lilac gills. It typically grows in forest environments.
Identifying Laccaria Bicolor
The cap of Laccaria bicolor is 2 to 6 centimeters in diameter, starting convex and flattening out with age. Its color varies, being deep tan or reddish-brown in wet conditions and fading to a paler buff or nearly white when dry, a characteristic that contributes to its “Deceiver” common name. The gills are a vibrant pinkish-lilac when young, though they can fade to a more subdued clay-lilac or buff as they mature and become covered in white spores.
The stem of Laccaria bicolor is fibrous, typically 5 to 14 centimeters tall and 5 to 10 millimeters thick. Younger specimens often show a lilac-colored mycelial down at the base, which fades with age. This mushroom is commonly found on forest floors, growing scattered or in groups, particularly under coniferous trees such as pine, spruce, and Douglas fir, as well as deciduous trees like birch and oak.
The Symbiotic Connection
Laccaria bicolor participates in a mutually beneficial relationship with tree roots, known as ectomycorrhizal symbiosis. In this arrangement, the fungus forms an extensive network of thread-like structures called hyphae, which surround the tree’s roots but do not penetrate the cells directly. This fungal network acts as an extension of the tree’s root system, significantly increasing its ability to absorb water and mineral nutrients from the soil.
The fungus provides the host tree with essential nutrients, such as phosphorus and nitrogen, extracted from the soil. In return, the tree, through photosynthesis, supplies the fungus with sugars for growth and energy. This exchange of nutrients supports the health and growth of both organisms, making Laccaria bicolor a valuable component of forest ecosystems. The genome of Laccaria bicolor was the first ectomycorrhizal fungus to be fully sequenced, providing insights into the genetic mechanisms behind this nutrient exchange.
Edibility and Similar Species
Laccaria bicolor is edible, though not highly prized. The caps are suitable for consumption and can be fried or used in mushroom soups, often described as having a taste similar to common button mushrooms. However, the stems are quite fibrous and are usually discarded due to their tough texture.
Identifying Laccaria bicolor requires attention to avoid confusion with similar-looking species. The most common look-alike is Laccaria laccata, which typically lacks the distinct lilac gills and violet mycelium at the stem base, or these colors are less pronounced. Other potentially confusing species include the Lilac Bonnet (Mycena pura) and the Lilac Fibercap (Inocybe geophylla var. lilacina), some of which can be toxic. The Lilac Bonnet has a smoother cap and a thinner stem. Always exercise caution; if there is any doubt about a mushroom’s identity, it should not be eaten.