Cladonia Species

This afternoon I took a brief exercise walk at Big Canyon Park in San Carlos. I'd not been here since I started to be more interested in lichens. It wasn't the most exciting lichen hike, but in one stretch (probably one of the less-walked stretches among the park's trail), in the dirt trail cut out bank, there were what appeared to me to be three different Cladonia species.

I understand that Cladonia are difficult. What I'd love to determine here is 1) are these three different species?, 2) are there identifiable species groups within Cladonia in this area that these fit into? (or, to put it differently, are there options for species identification here, so that next time I'll know what details to look for?

Thanks!

Posted on 11 February, 2018 02:13 by gyrrlfalcon gyrrlfalcon

Observations

Photos / Sounds

What

Pixie Cup and Reindeer Lichens (Genus Cladonia)

Observer

gyrrlfalcon

Date

February 10, 2018 04:27 PM PST

Description

New Cladonia for me in San Mateo. On the dead end extension of the Oak Meadow Trail.

Photos / Sounds

What

Pixie Cup and Reindeer Lichens (Genus Cladonia)

Observer

gyrrlfalcon

Date

February 10, 2018 04:36 PM PST

Description

Another one, but I’d guess it is a different species than the last one.

Photos / Sounds

What

Pixie Cup and Reindeer Lichens (Genus Cladonia)

Observer

gyrrlfalcon

Date

February 10, 2018 04:44 PM PST

Description

Yet another species of Cladonia. This one seemed to have less of a thallus.

Comments

@catchang , @kueda , @metsa , @tom_carlberg - thanks if you have time to take a look

Posted by gyrrlfalcon about 6 years ago

I’d help ya, Jennifer, but...I’m not on your list :)

Posted by robberfly about 6 years ago

Maybe @tom_carlberg can point you to Cladonia resources.

Posted by catchang about 6 years ago

Oh, @robberfly , it was inadvertent! I was working fast! The delightful @tui (Peggy Macres) was delivering dinner to the table!

Posted by gyrrlfalcon about 6 years ago

😘 I gotta tell ya, it’s maddenly frustrating - that group. Many species look the same.
The Cladonian Rosetta Stone has yet to be discovered...

Posted by robberfly about 6 years ago

Yes, of course...but...nothing? Are these at least different species? Or at least two species?

Posted by gyrrlfalcon about 6 years ago

Hi everybody, or if this post accidentally goes only to Jennifer, please pass it on... Jennifer, I think what you're asking is exactly what keys do, splitting species into groups according to characteristics they share. Here's how several keys break this group down. I'm including only a couple of the biggest breaks, so we don't get too bogged down. Remember that keys don't usually group according to how closely-related species are, just whether they have the same characteristics, i.e. squamule size:

From the Sonoran Flora, v.1; starts by testing with the carcinogenic para-phenylenediamine:

Thallus P+Yellow or P+Red............13
Thallus P- (no reaction)....................2
Unfortunately this key pretty much eliminates a field ID right from the start. Characters that show up later in the key are friendlier: cup-forming or not cup-forming; size of the goblets, fluorescent under UV light or not, size of the squamules on the ground, etc etc.

From Brodo's revised keys for N. America; he tries to avoid jargon & chemicals:

Podetia much branched......................................................................................2
Podetia unbranched, or branched once or twice, or podetia absent...............30 (this means that there are about 30 spp that match the first criterium)
Podetia without a cortex, surface dull and cobwebby (this takes you to the group of reindeer lichens, which all lack a cortex)

Podetia with a cortex

Main thallus mostly basal squamules; podetia absent or extremely small (<4mm tall)..................31

Main thallus mostly podetia, usually >4mm tall; basal squamules present or absent.....................42

Etc, etc, etc. To get to your species question, off the top of my head, you have two cup-forming species and one that is not forming cups, so at least two species. The two cup-forming obs have what looks to me like different size granules on the inside & outside of the cups, and my experience (based on lots of keying) tells me that this probably means two different cup-forming species. So my take would be three species in all. I have learned from folks like @robberfly that mammal and bird people don't use keys, and freely express their disbelief when they ask "What is this" and the answer comes back something like "Well, that depends whether it has alectorialic acid or not". But this is how it goes amongst photosynthesizers...

If you want to break things down for your geographic area specifically, you're going to have to do it yourself, using Sharnoff, the Consortium records, and the info contained in keys. I'm not trying to be harsh, it's just that all the lists and knowledge and decades of local experience available to vascular and bird and mammal and lepido people, it's just not available for lichen enthusiasts. Having said that, a reasonably analytical person can probably make something that can narrow it down, maybe even to species, using characteristics that can be seen in the field, without being (at the beginning) extremely knowledgeable about Cladonia. But by the time you're done, you will be!

Posted by tom_carlberg about 6 years ago

What are...”lepido people” ? :/

Posted by robberfly about 6 years ago

@tom_carlberg - That was VERY helpful, and not at all harsh. Honesty is honesty. I am going to have to get used to using keys. My guess is that effectively using keys means bringing samples home. I do not like the sound of carcinogenic chemicals (@metsa mentioned this today, too). When I start doing chem tests, it will not be with carcinogens in my clumsy hands. Again, I am very grateful for your stopping by to my humble page of beginner questions, Tom!

Posted by gyrrlfalcon about 6 years ago

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