In August of 2017, I wrote a journal entry about some of the difficulties for me, as a beginner, with the study of lichens. I have made some progress since then, for sure, but I am not yet utterly humiliated by my complaints back then. Here's a link to that entry - https://www.inaturalist.org/journal/gyrrlfalcon/11114-vexations-with-lichens
My primary complaint today is a simpler, more specific one. I spend a lot of my hiking and lichen-ing time in the Redwood (and mixed Redwood) forests of San Mateo county. The Coast Redwood (Sequoia semperviren) often has a greenish dust lichen on its trunk, near the base. Sharnoff says that Lepraria pacifica is one of the only lichens that will grow on the base of S. sempervirens, and this is attested, too, in the article about this species from Wikipedia by Lendemer (used in the species account here on iNaturalist - https://www.inaturalist.org/taxa/345911-Lepraria-pacifica).
So here are my vexatious questions
- IF there are other species of dust lichens that can tolerate growing on S. sempervirens, what are they?
- IF these other species exist, what is the relative percentage/likelihood of their occurring in San Mateo county or coastal California? Lepraria is not the most heavily populated among lichen Genus, with less than fifty worldwide (https://www.inaturalist.org/taxa/154184-Lepraria). Bordo lists twelve North American species, though that book adds that the genus has not been studied systematically in North America.
- CAN L. pacifica be told from L. finkii visually in the field? AND do we know if L. finkii can and does grow on Sequoia sempervirens?
- RELATED to that, what other crustose/squamulose lichens (either Lepraria or any look-alikes) DO adopt Sequoia sempervirens' bark as substrate?
I ask because my statistically justifiable but audacious naming of this green dust lichen on the base of a redwood tree in the midst of unrelieved redwood forest as Lepraria pacifica would constitute the FIRST San Mateo County record in iNaturalist. Since that seems an unlikely occurrence given what is written about L. pacifica's habitat preferences, I have to assume that everyone but me knows the answers to the questions above, OR knows they can't be answered, OR is afraid that there are crypto-species or unknown species out there that could throw this whole thing into doubt.
Thanks for listening! I'll tag some likely suspects in the comments section.
THANKS TO ALL who are generously sharing your lichen knowledge and cautions with me, a rank beginner 😊🌲(somewhere on this tree, there is lichen. You know it, and I know it. We await the day when there is an emoji for lichen, other than 🤯)