When: 2017-06-13

Collection location: Monterey Co., California, USA [Click for map]

35.8244°N 120.2977°W 445m [Click for map]

Who: J-Dar

Specimen available

On decorticated wood on the trunk of a very old red willow (Salix laevigata).

Thallus mostly not evident, very rarely showing greenish cortex on surface of wood. Apothecia single or occurring in small dispersed groups, about 0.5mm wide, with crusty white pruina, maroonish disks, and thalline margin, all parts C-, K-. Apothecia appearing to erupt when young, with ragged margins, becoming plane with entire margins. Hymenium and hypothecium hyaline, epiymenium light brown. Hymenium and epihymenium POL-, without crystals. Paraphyses with an enlarged pigmented apical cap.

Spores 8 per ascus, hyaline, simple, ellipsoid. 13.8×6.2µm


Immature apothecia

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Sounds good
By: Jason Hollinger (jason)
2017-06-22 23:12:38 CDT (-0400)

Thanks for following up!

Results of 100x with polarizing filters
By: J-Dar
2017-06-22 22:39:37 CDT (-0400)

I think the lack of POL+ crystals in the hymenium, as Jason suggested, shows this strongly as Lecanora hagenii. There are a few crystals in the epihymenium and maybe more in the epipsamma above that, in a few cross-sections, but almost a complete lack in the hymenium and also lacking in the amphithecial cortex.

Also, in going through Sliwa 2007 North American Lecanora dispersa group, I revised the following description of the apothecia:

Apothecia appearing to erupt when young, with “incised” margins (per Sliwa 2007 definition, “dentate, with sharp marginal segments”), becoming plane, sometimes flexuose, with mostly lightly crenate margins (=undulate, with rounded marginal segments).

It’s worth learning this
By: Jason Hollinger (jason)
2017-06-22 11:03:53 CDT (-0400)

I’ll send you some photos to help you see the difference. The one micro shot on waysofenlichenment gallery for L. dispersa is a poor example.

Want it?
By: J-Dar
2017-06-22 10:55:47 CDT (-0400)

Naw just kidding, thanks for the tips, i’ll work this up tonight after I finish the work that actually pays.

If this were my specimen
By: Jason Hollinger (jason)
2017-06-22 10:07:37 CDT (-0400)

I would do a bunch more sections, with a fresh blade just to be safe.

The photos suggest thicker cortex below, but no way to see the granules (or lack thereof) in the hymenium without polarizing filters.

By: J-Dar
2017-06-22 09:57:04 CDT (-0400)

First, this was in a wildland setting. Ok, so I’ll run another look at amphithecial and hymenial crystals under polarizing filters for sure, maybe I’ll get lucky with something obvious there. The amphithecial cortex on this specimen seems to be thin at the top and thicker at the bottom, based on the micro photos posted here. But, the rim is pretty distinct at 10-30x, and doesn’t seem to fade in age. Do you see anything in the photos that fits with the well developed cortex beneath the apothecium? I don’t, but not sure I’m looking at it right.

Revised comment
By: Jason Hollinger (jason)
2017-06-22 08:50:48 CDT (-0400)

Just looked through all my photos again. Blah. I had it wrong. By far the best character are the dispersa-type granules in the hymenium of L. dispersa. But I had the margin characters all wrong. Both have well-developed amphithecial cortex, both often with a good amount of gray/opaque POL+ granules in the upper amphithecial cortex. But all of the ones I’m sure are L. hageniihave a very thin almost indistinct cortex at the top of the rim, contrasting with a quite thick, distinct, entirely POL- cortex on the lower amphithecium. _L. dispersa, by contrast, has more evenly thickened cortex, which tends to be strongly POL+ throughout. Because the cortex is thick even on top, L. dispersa has a visible, well-developed margin at 10-30×. L. hagenii’s margin quickly becomes very thin and indistinct, even though hidden underneath the apothecium is a very well-developed cortex.

Sorry about that!

Looks like!
By: Jason Hollinger (jason)
2017-06-22 08:40:25 CDT (-0400)

Was this in an urban or disturbed habitat?

The thing I’ve found that you have to be careful of with these is to separate out epiphytic forms of L. dispersa. They are very subtly different.

L. hagenii has very few/patchy POL+ granules, either in/on the epihymenium or in the amphithecial cortex; and its cortex is very thin and poorly developed, usually with some haphazard cracking. Yours looks like all this fits.

L. dispersa by contrast has a scattering of POL+ granules throughout the hymenium (“dispersa-type” granules, shared with only a few other species, a good clean section is required to be confident of this, though, as a dull or pitted blade will drag granules from the epihymenium and/or epipsamma (stray dust on top of the epihymenium) through the section); distinct granules in the upper amphithecial cortex; and usually an uncracked margin with distinct cortex.

Most if not all of what I was calling L. hagenii from urban Pasadena turned out to be L. dispersa. One of the very few species that can tolerate Los Angeles pollution!

The REAL Lecanora hagenii?
By: J-Dar
2017-06-22 01:34:23 CDT (-0400)

Created: 2017-06-22 01:30:56 CDT (-0400)
Last modified: 2018-11-11 11:01:26 CST (-0500)
Viewed: 88 times, last viewed: 2019-08-19 18:35:53 CDT (-0400)
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