Bennett, James P. & Clifford M. Wetmore. Proposed list of extinct, rare and/or endangered macrolichens in Wisconsin. Mycotaxon 89: 169-180. 2004.

ABSTRACT: We propose that 41 species of macrolichens be listed for rare status in Wisconsin, along with 6 other species we think are now extinct in the state. Almost 60% of the species occur in the northern part of the state. Some of the extinct species occurred in the southern part. The rare and extinct species exist(ed) in 43% of the counties. None of the rare and extinct species are endemic to Wisconsin, and they represent 7% of the total lichen flora of the state. One species was last collected in 1884, but others were collected only recently. Forty-seven percent of the listed species are ranked critically imperiled (S1).

KEYWORDS: state ranks, disjunct, distribution, Midwestern states