Vexations with Lichens

I understand that lichens, as a group, are more difficult to learn than birds or butterflies. I’m OK with that. But I am frustrated by the seeming lack of good starter material. I am putting out this journal entry to record the vicissitudes of a beginner. Presumably I will look back and laugh at my naiveté in a few years’ time. Keep in mind that, while I hope I am “smarter than the average bear,” I am no biologist in any sense of formal training and/or understanding.

The Taxonomy – Lichens can’t be definitely separated from other fungi? No way to check iNaturalist to see what species of lichen have been seen in an area without checking all the fungi, for instance? If lichens are distinct from fungi by nature of the symbiosis with algae, why isn’t that reflected taxonomically? The fact that the foliose/fruticose/crustose distinction doesn’t appear to follow/reflect taxonomic categories really confuses me, too.

Resources – As a birder, I am spoiled by the amazing range of field guides we have, and their depth of detail in both descriptions and illustrations. With the lichen materials I have used so far, I find that the descriptions are shot through with specialized vocabulary that creates a steep learning curve, if not becoming downright tautological/autological and circular. Photographs don’t describe relative size, or give relevant size comparisons. Range maps would help, too (I see a citizen-science opening here, for more lichen observers to be widespread and recording everything they can find, state-by-state, county-by-county, habitat-by-habitat).

Taxonomy + Resources – I have no doubt that Stephen Sharnoff’s California Lichens is an excellent guide. But it is frustrating for me as a beginner. Putting the species in alphabetical order within the f/f/c framework only made the taxonomy more opaque for me. No diagrams on lichen parts, no schematics. The photos are beautiful, but with little sense of scale or size. Range descriptions are vague. He’ll describe a lichen that I think is matching with what I am looking at, then list three simialr species that he hasn’t illustrated. Aarrgghh!

What might help? - I am reminded of how, before Roger Tory Peterson’s breakthrough, bird descriptions had to be ordered according to a template. This meant you might not learn about the American Robin having a red breast until 2/3 of the way through a description! I feel something similar is happening with lichens (again, hedging caution around my naiveté). It seems to me that the way to build ID knowledge in most taxa is going from the coarsest to the finest level on three fronts simultaneously: visuals, range/habitat and likely species of confusion. Perhaps crustose:lichens::empidonax:birds::skippers:butterflies. But there are still some categories (like Caloplaca) that can be taught and recognized (how many ways does lichen nomenclature play with “fire” and “candles”??) – just as Empidonax can be told from Phoebes (Sayornis). Could schematic drawings of a few different types of lichens, naming the parts, be made available?

OK, now I am just ranting! Really, I am loving lichens, because it means intensive discovery of small things, really digging into the immanence of one’s environment. I will look back and laugh, but if some of my exasperation helps me to later help beginning lichen students, it will have been worth it to parade my ignorance.

Posted on August 09, 2017 06:22 PM by gyrrlfalcon gyrrlfalcon


"Lichen" is more of a lifestyle than an evolutionarily conserved trait. Lichenization is thought to have evolved (and/or been lost) in several separate lineages of fungi, so as long as taxonomy roughly reflects phylogeny, there is no single taxon that contains all lichens and only lichens, just like there is no single plant taxon that contains all trees and only trees. We don't have good species categorization schemes beyond taxonomy on iNat, which is definitely frustrating for people who want to categorize the world in other ways (trees, tidepool creatures, things that are red, etc).

There is definitely a lack of good literature. Sharnoff's book is a good start, but as you point out it has the very large flaw of not being comprehensive, so when you find something close, you can't exclude other possibilities. Lack of systematic photos with scale is a problem, but even more glaring is the lack of pictures of the lower surfaces of foliose lichens and detailed shots of diagnostic features in general. Alphabetical ordering definitely favors the expert over the newbie, but beyond the foliose / fruticose / crustose / squamulose divisions, it's very hard to put lichens into groups that seem "natural."

Have you tried Bruce McCunes Macrolichens of the Pacific Northwest? While it's somewhat more technical than Sharnoff's book and it doesn't cover everything in our area, it's much, much better about illustrating diagnostic features, including the ever-important lower surfaces of foliose lichens. He also has a new book out on crusts that I've yet to try.

But yeah, I agree there needs to be a better guide to lichens that focuses on what you can identify without a microscope. Whether such a thing is really possible given our depauperate state of knowledge about basics of distribution and identification and the fluid state of fungal taxonomy... not sure.

Posted by kueda over 6 years ago

I feel your pain! :) There are a number of large groups of somewhat or largely neglected living things that are very difficult for an amateur to develop any comfort with...

Have you tried the California Lichen Society? They have regular ID workshops in the Bay Area - I am a member, although I've never had the time to do much with this group...

Posted by kschnei over 6 years ago

Thanks both. I have joined the California Lichen Society and intend to participate. That's part of why I wrote this journal entry now - these are my reflections before I genuinely start to learn from others. Tomorrow I am taking a dedicated lichen hike with JJ @metsa , and I hope to attend a lichen event in October.

Posted by gyrrlfalcon over 6 years ago

Ken-ichi, I love the ""Lichen" is more of a lifestyle than an evolutionarily conserved trait," and the taxonomic comparison to trees. Together they are very helpful. @kueda

Posted by gyrrlfalcon over 6 years ago

@gyrrlfalcon - well done! You've perfectly captured the consternation and amusement felt by some who are drawn to lichens. I certainly felt completely overwhelmed when I first started exploring lichens. Keep in mind I'm still a beginner AND have no background in botany (which may have helped in some ways). But I was drawn to these beautiful and mysterious symbiotic organisms in a way that kept me coming back for more and more. You make a good point about the lack of "starter materials", but there are several experiences I found useful. 1) Intro to Lichen workshops: super helpful for grasping the basic concepts. Several take place in the Bay Area and involve 1-day classes often with a lichen hike in the field. The instructors are extremely helpful; 2) Learning the relevant structures, bits, and pieces. This takes a bit of time because many are small. However, much of lichen ID depends on knowing these structures. 3) books and online resources., I love lichen books, especially Scharnoff, Brodo, and McCune's books. There are several good online resources too; 4) Lichen Keys. sigh They are still frustrating, but the process of going through keys has helped refine my ID skills. @tom_carlberg created an easier-than-average lichen key for our area. And finally, 5) practice, practice, practice (and make mistakes). I've spent the majority of the weekends in the past 3.5 years "lichen hunting". Without iNat and the California Lichen Society, there is no way I would have been able to learn so much. It’s worth the investment in time, as you probably know from your music background. :) See ya in the morning for a lichen-n-bird hike.

Posted by metsa over 6 years ago

Very useful article and associated comments, thanks. I've just begun to scratch the surface of learning lichens. There is much to learn, I think I'll try to find a class here in the Seattle area.

Posted by brewbooks over 6 years ago

Hi all - Not sure if what I have to say will address gyrrlfalcon's concerns or not; it's been a long time since things like naming of lichen parts has been an issue for me. But let's see...

Taxonomy - Your comment that lichens can't be separated from other fungi... If a symbiotic lichen became a taxonomic entity separate from other fungi, what would you do with other symbioses/mutualisms?

Resources - Some (by no means all) of your concerns can be addressed by getting a copy of Brodo, who has range maps and photos with an indication of scale. It will not give you a comprehensive guide, and certainly not for California. But it's very user-friendly. If the ranges of lichen species in Sharnoff are "vague", it's mostly because those distributions are still being discovered; it's very very easy to add to that knowledge; i.e. see the article on Dye Creek in the current CALS Bulletin.

As for "specialized vocabulary", welcome to the monkey house! Birders (and plant people) are indeed spoiled; the specialized vocabulary for those disciplines were learned as children (or undergrads; oh, wait...): beak, wing, feather, throat; flower, petal, leaf, root. Birds and plants are important to people, mostly I suspect because we eat them. Lichens? Not so much. So my advice is to start memorizing! I have mentioned repeatedly in the workshops I present that the disparity between plant people and lichen people is probably about 1000:1. Probably similar for bird:lichen. No wonder Ken-ichi mentions the "lack of good literature". And no wonder there are more and better refined resources for birds and plants!

I also think that birders in particular are disadvantaged when they start to look at photosynthesizing organisms, and discover (or trip over) the concept of the dichotomous key. Robberfly once told me that bird and butterfly people do not use keys to ID their species. I was a bit dumbstruck, but eventually realized that there are fewer birds and butterflies than there are plants or lichens.

In addition to McCune & Geiser (which has an illustrated glossary), here are some free resources. They are for B.C., but they include very well-illustrated glossaries for each volume, and the illustrations are placed at pivotal couplets in the keys, so the part being talked about has the illustration at hand. And they are free resources. Unfortunately, they came out in the 90s when a megabyte was a lot to download, so there are many files for each volume.

Lichens of British Columbia part 1 (foliose):

Lichens of British Columbia part 2 (fruticose):

Posted by tom_carlberg over 6 years ago

And if that's not enough, here is something from my workshop handouts. Please do not get overwhelmed, but I have always thought that information should be shared...

Brodo, I.M., Sharnoff, S.D., Sharnoff, S.D. 2001. Lichens of North America. Yale University Press, New Haven Ct. 795pp.
Bruce McCune’s web page. Contains links to keys, books, info.
Bulletin of the California Lichen Society. Membership/subscription starts at $20 for individuals. The Society makes back issues (html & .pdf) available FREE online at
California Lichen Society home page. Links to back issues of the Society’s Bulletin, and other resources, including field trips, library resources, conservation activities, listserver.
Checklist of California Lichens, Tucker & Ryan. A valuable resource for Californians. Bear in mind that the species in the checklist are reported from the literature, but possibly not reviewed by the authors.
Checklist of North American Lichens. Includes synonymy. ESSENTIAL. updated about every two years.
Consortium of North American Lichen Herbaria (CNALH) . Great search engine for discovering range and distribution of lichens in North America.
Doell, J & R. Doell. 2009. Miniguide to some common California lichens, 2nd edition. 50pp, color, $14. Available from California Lichen Society,
Goward, T, B. McCune, D. Meidinger 1994. The lichens of British Columbia illustrated keys. Part 1 – foliose and squamulose species. British Columbia Ministry of Forests Research Program, Victoria. 181pp. available FREE online:
Goward, T. 1999. The lichens of British Columbia illustrated keys. Part 2 – fruticose species. British Columbia Ministry of Forests Research Program, Victoria. 319pp. available FREE online:
Hale, M.E., Jr. Cole, M. 1988. Lichens of California. University of California Press. Out of print. A dated but historically valuable pocket-size guide to both crustose and macrolichens in the state.
Key to genus for all Pacific Northwest lichens. Available FREE online. A good resource even in central Calif., if your lichen is being difficult in the early stages of identification.
McCune B., L. Geiser 2009. Macrolichens of the Pacific Northwest 2nd edition. Oregon State University Press. About $30.
Nash, T.H. III with many contributing authors. 2002 - 2007. Lichen Flora of the Sonoran desert region, volumes 1-3. Lichens Unlimited, Arizona State University. More and more useful the further south you go. Highly technical, about $60/volume.
Recent Literature on Lichens (RLL). Query page for database of lichen literature, from 1536 to present. ESSENTIAL lit review tool; comprehensive for lichen literature globally.
Steve Sharnoff’s photos. Beautiful copyrighted photos.
University of Oslo photo library. Huge copyrighted photo library, high & low-resolution.
Sharnoff, S. A field guide to California lichens. Yale University Press, $32.50.

Posted by tom_carlberg over 6 years ago

@tom_carlberg - I am honored (and embarrassed) to have you read my early musings. I am getting better already, thanks to help from my friends!

Posted by gyrrlfalcon over 6 years ago

See you at Sagehen in October?

Posted by tom_carlberg over 6 years ago

That's a big weekend for Sequoia, so not this year. But Sonoma in late October...

Posted by gyrrlfalcon over 6 years ago

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