Observation 197723: Buellia De Not.

When: 2015-02-01

Collection location: Atascadero, California, USA [Click for map]

35.4514° -120.6437° 280m

Who: J-Dar

No specimen available

On old wood ranch fence. Thallus grey, apothecia sessile, black, no yellow streak. With Thelomma occidentale observation 194138, Cyphelium tigillare observation 197607 and others.

Spot test thallus K-, it just turned dark green like it burned off a grey pruina. C. inquinans is supposed to be K+ yellow to reddish brown; C. pinicola is K- and the apothecia of this look a lot like pinicola, all shiny black. Maybe a greyish C. pinicola?

Proposed Names

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Used references: Nash V2 and MO and CNALH
52% (3)
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Add Comment
The thallus is way too well-developed for Amandinea punctata
By: Jason Hollinger (jason)
2015-02-17 05:51:07 CET (+0100)

…but it is extremely variable in that character, alas. The K- reaction definitely makes things difficult! My partner just bought an excellent used compound microscope from a school sale, and I believe there may be several left. It was only ~$240(?) I can get you more info on that if you are interested.

What about
By: J-Dar
2015-02-14 19:42:03 CET (+0100)

Amandinea punctata?

Long shot maybe, i still don’t have a compound scope to check spores or other micro features…But seems to fit and is K-. I tried hard to get K+Y and could maybe convince myself i may have seen it, but doubtful if I keep my grip on reality.

Here’s some photos for comparison
By: Jason Hollinger (jason)
2015-02-03 08:48:33 CET (+0100)

Cyphelium inquinans from eastern Washington: observation 197979

I don’t think I’d ever noticed the ontogeny of the apothecia of that species before. The exciple completely covers the spore mass at first like a peltate indusium, then slowly unfolds as the spore mass builds up and forces it open. Notice the white pruina around the rim of the exciple, too. That is supposed to be typical of the species.

This doesn’t look mazaediate
By: Jason Hollinger (jason)
2015-02-02 05:58:25 CET (+0100)

Your most close-up photo really makes this look like a normal apothecium. I woudl expect to see some dusty spores piling up on top of the disks, even if it had just been washed completely clean.

I’d have said Buellia for sure… but all of the Buellia I can think of with really thick gray thallus like this are K+y, so you’re right back where you started. Other options include Lecidella euphorea (K+y again!) and maybe a Lecidea (can’t think of any on wood with thick white thallus, though).

Sort of running out of ideas. Falling back on less likely scenarios… Maybe it really is K+y but it’s just one of those specimens that’s hard to see because it dissolves the gray cortex so quickly that it’s only fleetingly yellow? If so, just brushing it with a really tiny amount of K will sometimes be effective — enough to see the atranorin reaction, but not enough to dissolve the cortex and expose the algae and substrate.

Another way to confirm Buellia – even without a compound microscope – is to do a thin vertical section of an apothecium with a sharp razor blade. Even under a dissecting scope, you will be able to see the dark brown spores streaking the otherwise white hymenium. Cyphelium will just be a big mass of black-brown spores, so it will just sort of mash up and look entirely brown inside when you go to section it (only the very youngest mazaediate apothecia still have an intact hymenium). Lecidella and Lecidea will be pure white inside (but maybe with dark brown area below the hymenium, and often with greenish or bluish tints to the lateral walls and upper surface). Obviously this is a lot more reliable with a compound scope, but with practice you can definitely learn to read this under a dissecting scope just as reliably.

Created: 2015-02-02 02:56:13 CET (+0100)
Last modified: 2016-05-08 21:48:50 CEST (+0200)
Viewed: 90 times, last viewed: 2017-06-20 02:55:37 CEST (+0200)
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