Sticta fuliginosa (Hoffm.) Ach.
Peppered moon lichen
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Basis for Listing
Sticta fulginosa has an Appalachian-Great Lakes distribution pattern in eastern North America, and is also found along the Pacific Coast and in the mountains of Colorado, Arizona, and New Mexico. It was formerly quite common in Minnesota along the Lake Superior shore and around inland lakes and bogs. Today, there are only a few extant populations known in Lake and St. Louis counties. Sticta fulginosa was listed as a special concern species in Minnesota in 1984.
Sticta fulginosa is a foliose (leaflike) lichen. The thallus (lichen body) is greenish to dark brown with broad, short lobes, 5-10 cm (2-4 in.) across (Hale 1979). The edges of the lobes are rolled somewhat downward. On some specimens, ridges can be found on the upper surface of lobes. Mature specimens have abundant, tiny, very fine, cylindrical to coralloid isidia (finger-like projections) on the upper surface of the lobes that confer to the whole lichen a dull, granular appearance. The lower surface of the thallus is pale brown and covered with an almost white tomentum (appears felty). Sticta fulginosa contains blue-green algae (Wetmore 1981; Brodo et al. 2001).
Sticta fulginosa is very rare. Where it exists, it is found on conifer and hardwood trees in mature, moist forests and bogs. Betula alleghaniensis (yellow birch) and Thuja occidentalis (northern white cedar) are preferred substrates. This lichen prefers partial shade in areas that tend to retain moisture, such as cedar swamps, and is often growing on the lower trunks of trees, 9-15 dm (3-5 ft.) above the ground.
Biology / Life History
Reproduction is achieved by dispersal of fractured isidia, perhaps distributed on the feet of birds but more likely driven by wind, water, or insects.
Conservation / Management
The preferred habitat for S. fulginosa is wet, old-growth forests forests and bogs. Because most of these areas are diminishing as a result of increasing demands for forest products and growth pressures, lichen populations are diminishing as well. Other threats to the survival of S. fulginosa include fire; air pollution, as this lichen is reported to be sensitive to sulfur dioxide and nitrogen; and climate change or habitat dessication (Wetmore 2002). This lichen is barely surviving in cool moist locations, so increases in temperature or decreases in moisture and humidity would likely eliminate this rare species. Wetmore (U.S. Forest Service 1999) projects that any disturbance of wet, old-growth forests could threaten its survival in our area.
Conservation Efforts in Minnesota
Scientists are searching for this and other rare lichens in an attempt to identify and possibly preserve local populations.
References and Additional Information
Brodo, I. M., S. D. Sharnoff, and S. Sharnoff. 2001. Lichens of North America. Yale University Press, New Haven, Connecticut. 795 pp.
Hale, M. E. 1979. How to know the lichens (Pictured Key Nature Series). Second edition. William C. Brown Co., Publishers. Dubuque, Iowa. 246 pp.
U.S. Forest Service. 1999. Population viability assessment in forest plan revision. Statement of purpose and reason. Draft species data records: Sticta fulginosa. United States Forest Service, Region 9.
Wetmore, C. M. 1981 (revised 2005). Keys to the Lichens of Minnesota. Department of Plant Biology, University of Minnesota, St. Paul, Minnesota. 92 pp.
Wetmore, C. M. 2002. Conservation assessment for Sticta fulginosa (Hoffm.) Ach. United States Forest Service, Eastern Region, Milwaukee, Wisconsin. 12 pp.