Dermatocarpon moulinsii (Mont.) Zahlbr.
A Species of Lichen
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Basis for Listing
According to Hale (1979), Dermatocarpon moulinsii occurs in the western United States east to the Rocky Mountains and in the Black Hills of South Dakota. This species has also been found on Isle Royale. The rare outlier population of D. moulinsii in the Great Lakes region follows a disruption pattern similar to several other lichen species of western North America. Dermatocarpon moulinsii was collected only once in the state, by Bruce Fink in 1896. The locality was given as the Minneapolis area. Dermatocarpon moulinsii may have been found along the river bluffs, but air pollution and urban expansion have destroyed the original population. Additional localities for this species may be found when future surveys are conducted in the state. Dermatocarpon moulinsii was listed as an endangered species in Minnesota in 1984.
Dermatocarpon moulinsii is a foliose (leaflike) lichen. The thallus (lichen body) is umbilicate (attached to the substrate at a single point near the middle of the thallus). It has a gray, pruinose (frosted appearance) upper surface and sunken perithecia (flask-shaped fruiting bodies that open by a small pore). The lower surface of the thallus is dark brown or black, and has numerous short, branched rhizines (fungal rootlike structures). When wet, the thallus undergoes no color changes?when subjected to chemical spot tests, this species does not react. Microscopically, the spores for this lichen are clear, non-septate, measuring approximately 13 µm x 6 µm. The alga in this lichen is green (Wetmore 1981).
This species grows on bare, exposed rock outcrops. Sometimes the rock or soil nearby is calcareous. In this region, the species is occasionally found on the north sides of rock cliffs.
Biology / Life History
Dermatocarpon moulinsii reproduces sexually, with the spore dispersal by wind, water, or other means. Once spores find suitable habitat, they must also locate the appropriate algae to successfully form a new lichen thallus.
Conservation / Management
The only known population of this lichen in Minnesota was probably eliminated long ago, so habitat loss is an obvious threat to any surviving populations. The main threats appear to be pollution, encroachment of development, and perhaps quarry operations.
Conservation Efforts in Minnesota
Scientists are searching for this and other rare lichens in an attempt to identify and possibly preserve local populations.