This page links to 17 index pages: 16 of them provide links to photos of identified lichens, including those that are identified to genus but not to species. It also links to an index page providing access to about 300 "mystery" lichens that are completely or partially unidentified, and a page that links to topics in lichen natural history. There are about 7,000 photos on the site, illustrating approximately 1,275 species. Most of the photos were taken for the book,Lichens of North America, with text by Dr. Irwin Brodo, published in 2001 by Yale University Press. There are two photos by others. Almost all are from the continental U.S. and Canada, but there are some from Baja California, Mexico, and a few from southern France.

Most of the identifications for the photos were made by Dr. Brodo from voucher specimens that Sylvia Sharnoff and I collected between 1973 and 1998. A smaller number of images were taken by me between 1999 and 2007 and were identified by a number of other lichenologists, including Stephen Clayden, Mariette Cole, Theodore Esslinger, Trevor Goward, James Lendemer, Bruce McCune, Thomas H. Nash III, Roger Rosentreter, and others. Several hundred newer images (and some older ones) of species that occur in California,were identified by Kerry Knudsen, Trevor Goward and Curtis Bjork. A number of lichenologists have also contributed names, or made corrections, from looking at the photos on the website, among them Einer Timdal, Brendan Hodkinson and others. Enormous thanks are due to all who helped! In particular, I owe more than I can express to Ernie Brodo, without whose generosity, energy, and steadfastness our project with lichens would have never developed beyond a passing fancy. Special thanks also to Kerry Knudsen who corrected numerous errors and contributed many new names and information. For the sake of simplicity I have not italicized the scientific names on the website.

I've attempted to keep the names current with the North American Checklist by Theodore Esslinger, but there many recent changes and catching them all is difficult. If you see any errors, I'd appreciate your letting me know! You can email me, Stephen Sharnoff, at stevesharnoff@gmail.com

A Field Guide to California Lichens, which illustrates and describes approximately 500 species, is available from Yale University Press, or from your local bookstore.

I am making corrections to the names and information on the site on an ongoing basis, adding additional photos from my archives and new identifications. The most recent revision, is May, 2024, but I haven't attempted to incorporate name changes from the past couple of years.

The informational website about lichens, www.lichen.com is no longer functional at that address, but its contents have been incorporated into this website, at Lichen Information.