Lactarius fuliginellus Smith & Hesler
A Species of Fungus
Basis for Listing
Lactarius fuliginellus has been collected twice from a single location in Anoka County, but has not been found elsewhere in the state. It is at the northwestern limits of its known range in Minnesota, and its preferred habitat with Quercus spp. (oaks) and hardwoods in low areas is vulnerable to disturbance from human activity. Lactarius fuliginellus was listed as a special concern species in Minnesota in 1996.
Mushroom caps are 35-100 mm (1.4-3.9 in.) broad and shallowly depressed. Cap surface is dry and velvety, the color uniform or with paler spots or paler margin, azonate (lacking concentric bands), dark yellowish brown, and may become paler in color or be deep brown in color. Latex (milky fluid) is white and copious. Flesh and gills stain light orange or light yellowish pink (in 15 minutes). Odor is mild. Taste of context mild to mildly disagreeable; latex is mildly bitter. Gills close when young, becoming subdistant (fairly well separated) with age, 4-10 mm (0.2-0.4 in.) broad. Gill color when young is yellowish white, becoming more yellow to pale orange yellow.
Lactarius fuliginellus apparently prefers hardwood habitats in areas that are near water or that are periodically inundated. The Michigan type collection was from under hardwoods at the edge of a bog. In Mississippi, it was found in bottomland hardwood forest. The Minnesota population was found in two successive years in Anoka County. The species was located in leaf litter under hardwoods, primarily Quercus spp. and Rubus spp. (blackberry), in a low area that holds water in wet years.
Biology / Life History
Fully grown fungi disperse spores into the air, which plant themselves in the ground, growing into hyphae, or fungal filaments. Hyphae from two different fungal organisms meet, fuse, and form a mycelium, the filamentous vegetative portion of a fungus (excluding the fruiting/reproductive phase of the life cycle). A small, button-shaped fungus forms, pushes above the ground, and obtains a covering called a veil. When the veil ruptures, an adult fungus grows.
Conservation / Management
The preferred habitat of lowland hardwoods and the location in Anoka County are vulnerable to disturbance from human activity, including habitat loss and changes in hydrology. Ectomycorrhizal fungi in general are sensitive to nitrogen deposition and other forms of pollution that affect the soil. The distribution of L. fuliginellus in North America may be poorly known because this species is easily mistaken for L. fumosus and can only be reliably separated by microscopic characters.
Conservation Efforts in Minnesota
Lactarius fuliginellus was collected twice by an amateur mushroom hunter and studied in fresh condition by P.R. Leacock. It was not otherwise recorded during a several year survey of Lactarius in the state (P.R. Leacock, unpublished data), although lowland oak/hardwood forests were not specifically searched. Further surveys are needed to accurately document its distribution and abundance, but based on current knowledge its population size within the state appears to be small.
References and Additional Information
Hesler, L. R., and A. H. Smith. 1979. North American Species of Lactarius. The University of Michigan Press, Ann Arbor, Michigan. 841 pp.
Smith, A. H., and L. R. Hesler. 1962. Studies on Lactarius - III, the North American species of section Plinthogali. Brittonia 14:432.