Observation 221375: Coenogonium pineti (Ach.) ined.
When: 2015-09-13
No herbarium specimen


Copyright © 2015 Jason Hollinger (jason)
Copyright © 2015 Jason Hollinger (jason)
Copyright © 2015 Jason Hollinger (jason)

Proposed Names

3% (2)
Used references: M.Beug Ascomycete Fungi of North America
16% (2)
Recognized by sight
84% (1)
Based on microscopic features: algae trentepohlia, spores 8 per ascus, 1-septate, ~10×3µm

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Yes, always Trentepohlia
By: Jason Hollinger (jason)
2016-01-10 13:53:53 PST (-0800)

There’s a cryptic comment in the British Flora, though: “The genus differs from Coenogonium only in the algae, and as this is phylogenetically not significant, Dimerella is increasingly merged with that genus.” … But both genera have Trentepohlia, so in what way does the algae differ between the two genera?! I think this is a misleading (or downright incorrect!) statement. I think the difference is Dimerella contains crustose species, Coenogonium filamentous. But as there are species with both a crustose basal thallus and filamentous “aerial” thallus, the distinction between the two forms is blurred. Throughout lichenology, wherever one genus was separated into a crustose group and a fruticose group, inevitably the split has proven to be para- or polyphyletic. This would appear to be no exception.

And is Trentepohlia
By: Danny Newman (myxomop)
2016-01-10 13:41:57 PST (-0800)

always the algal associate, as in the case of the charming little thatched brackets of C. leprieuri?

Yeah, there are two species that go all the way to the boreal
By: Jason Hollinger (jason)
2016-01-10 13:02:04 PST (-0800)

At least in North America. Coenogonium luteum and C. pineti (both also sometimes placed in Dimerella).

And here
By: Danny Newman (myxomop)
2016-01-10 12:59:22 PST (-0800)

I always thought this was a tropical genus. Neato!

Yes, that I+r hymenium is screwy
By: Jason Hollinger (jason)
2016-01-09 11:51:32 PST (-0800)

I’ve seen several specimens of Dimerella lutea, but I’ve never bothered to do a straight-up I test on the medulla (I always do K/I instead). I wonder if the literature are all just copying the same (incorrect) source over and over again. It is, after all, K/I+ deep blue. Maybe it was an innocent typo back in 1893 or something like that! And no one ever bothers to check because it’s such a distinctive genus!

I’ll dig up a verified specimen of D. lutea later today and check it.

Meanwhile, there are no other 1-septate genera with trentepohlia so far as I can tell. I was hopeful for Gyalecta for a while, but there are no 1-septate species. It’s always 3-septate or more, up to muriform.

Anyway, this is definitely lichenized. There is trentepohlia inspersed into the base of the apothecia. That’s more than just facultatively “dining on” algal by-products!

What a pleasant surprise.
By: Andrew Khitsun (Andrew)
2016-01-09 11:32:45 PST (-0800)

I thought for a second it’s a lichen, but defaulted to fungus later on (still deciding to send a specimen to a specialist for checking out). Dimerella pineti , according to Thomson, in Wisconsin is “known from the north, and isolated specimen from Sauk County” (where Devil’s Lake is located). The color of I+ still bothers me though.

Added close-up photos
By: Jason Hollinger (jason)
2016-01-09 10:38:42 PST (-0800)
This is lichenized!
By: Jason Hollinger (jason)
2016-01-09 00:41:43 PST (-0800)

Only problem with the material Andrew sent me is that the hymenium is distinctly I+ red-brown, but is reported to be I+ blue. All else matches well.

This was one of the few times when I wasn’t sure whether it was a lichen or mushroom
By: Andrew Khitsun (Andrew)
2015-11-01 07:09:15 PST (-0800)

It seems to be comfortable both on slime-covered wood and mosses. There is a description of Roseodiscus subcarneus in Ascomycte Fungi of North Ameica that caught my attention, but that species and two related ones have long stalks. Critter in front of you is sessile when looked under microscope. The fruit bodies are tiny – much less than 1mm, and appear to the naked eye like a dust on moss.

Created: 2015-11-01 06:59:43 PST (-0800)
Last modified: 2016-01-09 10:38:17 PST (-0800)
Viewed: 97 times, last viewed: 2016-10-25 21:22:11 PDT (-0700)
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