Observation 195937: Caloplaca stipitata Wetmore
When: 2015-01-10
(35.4514° -120.6437° 280m)
Who: J-Dar
No herbarium specimen

Notes: On old wood ranch fence. Thelomma mammosum (Obs #194138) also visible in first photo.

Proposed Names

-61% (2)
Recognized by sight
30% (2)
Recognized by sight
61% (2)
Recognized by sight

Please login to propose your own names and vote on existing names.

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Yes, all orange Caloplaca are K+r
By: Jason Hollinger (jason)
2015-01-19 08:50:23 PST (-0800)

But still, good calibration for your new “K”. (And that intense immediate K+ wine-red reaction never really grows old. :) I used NaOH for a long time, and never found any difference. Nevertheless, I’ll bring some KOH (and PPD and UV and other goodies) when I see you in February.

K+ Red
By: J-Dar
2015-01-19 08:24:56 PST (-0800)

Instant crimson red color change from Sodium Hydroxide 10% solution. Not specific to any particular part of the lichen, however, but species descriptions for C. stipitata and others, like c. durietzii, are basically K+ all over. Photo added.

As always…
By: J-Dar
2015-01-11 08:25:03 PST (-0800)

Thanks for the informative responses!

Very difficult genus
By: Jason Hollinger (jason)
2015-01-10 21:53:51 PST (-0800)

There are a few resources that might help. Send me your email address and I can email you a couple of papers and informal keys. The best comprehensive treatment for southern California, however, is in volume 3 of the Sonoran Flora, which unfortunately I don’t have an electronic copy of.

It actually keys out pretty readily in the Sonoran Flora:

Key I (pg.183): on bark, thallus gray or orange
1b. apothecia orange (not dark red-brown) … 4
4a. thallus orange (parts are gray, but that would lead to holocarpa which is clearly wrong) … 5
5a. thalline margin of apothecia dominant, proper margin thin or invisible … C. stipitata

This proper margin versus thalline margin character is hard to see, esp. in photos. The alternative to that couplet is C. durietzii, an inland species mostly from southeastern AZ, but with a couple coastal records from Baja. _C. stipitata, on the other hand, is abundant on the Baja coast up to San Diego, the Channel Islands (and I’ve seen one poor specimen on Palos Verdes peninsula).

The more I think about it, the more confident I get. It’s just a species I’m not familiar with, and a genus that has way too many subtle species, that I tend to err on the side of caution. I’ll switch my votes to make stipitata “promising” and the genus just “could be”.

Caloplaca key
By: J-Dar
2015-01-10 21:03:54 PST (-0800)

Jason, I don’t have a key for Caloplaca, what would we need to confirm species ID?

Created: 2015-01-10 19:46:57 PST (-0800)
Last modified: 2015-01-19 08:28:14 PST (-0800)
Viewed: 60 times, last viewed: 2016-10-27 05:00:02 PDT (-0700)
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