These pages, describing "Rare Lichens of Wisconsin" include three lists of Wisconsin lichens, described below, which pertain to species' rarity and possible need for protection. The lists are based primarily on information in Dr. J. W. Thomson's book Lichens of Wisconsin (L of W), which was published in 2003. Nomenclature for lichens on these lists generally follows Esslinger and Egan (1995) (E & E). The exceptions are new names adopted by E & E for which Dr. Thomson considered to be based on weak taxonomic evidence at the time. In these instances, we used the older name, and noted the E & E name after an equal sign.

A. Lichenized fungi which may warrant listing for protection. In addition to being rare (see B), these species show some evidence of either decline or stress to populations (contraction of past range, or professional opinions of Dr. Thomson and Dr. Clifford Wetmore, University of Minnesota), and so should be considered for protected status.

B. Rare lichenized fungi of Wisconsin.This list includes all lichen species which are currently assessed as rare in the state. The main criteria for placing a species on this list were 1) the existence of no more than 5 records in the state; and 2) knowledge by Dr. Thomson that the genus has been at least moderately well-collected in the state. A subset of these species (see A) are suggested for protected status.

C. Lichenized fungi which appear rare due to undercollecting. The species on this largest list appear rare, but the genera have been so poorly surveyed that they are quite possibly common and merely undercollected in the state. After more inventory work has been completed, some of these species may eventually be considered genuinely rare.
 

It would be very useful to have further records of any of the species on the three lists. Anyone who has records of these species: please send the information to us. For specimens housed in major public herbaria please send information about records including specimen number, name of collector/determiner, habitat and location (including county) in Wisconsin, and date of collection. Clear photocopies or electronic records of specimen labels are fine. For records in private collections, the WIS Herbarium staff would like to see a voucher specimen.

  REFERENCES

Esslinger, Theodore L. and Robert S. Egan. 1995. A sixth checklist of the lichen-forming, lichenicolous, and allied fungi of the continental United States and Canada. The Bryologist 98(4):467-549.

Thomson, John W. 2003. Lichens of Wisconsin. Wisconsin State Herbarium.