Lichens are an important component of the environment, contributing to the diversity, nutrient cycling, animal habitat, and soil amelioration in ecosystems. Vegetation surveys for Washington state are now including cryptogams, such as lichens, realizing their importance as indicators of forest health. Some significant lichen species are infrequently found in Washington state and efforts to monitor their status has become a high priority. Of special interest are lichens associated with a Mediterranean climate found in the San Juan Islands, Whidbey Island, and the northeastern portion of the Olympic Peninsula. Following a preliminary survey completed in 1997, a list was compiled for the Department of Natural Resources and the Natural Heritage Program to determine the rarity of lichens in the state. The list consists of 110 Washington lichens. Thirty-five species are listed as Priority One, indicating that they are endangered, threatened, or sensitive. A second list of lichens, Priority Two, consists of those needing to be monitored, due to questionable status. Accurate field data and identification are required to ascertain the status of these lichens. The present list may reflect under collected species rather than rarity. Particularly problematic are the crustose lichens, due to difficulty in species determination. Distributions for these lichens are just beginning to be recorded. As taxonomic treatments of crustose lichens are developed and qualified lichenologists are employed in the state, more species are likely to be added to these lists.

Key words: lichens, Mediterranean, rare, state, Washington