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Collection_Number(s): ACD0147, MF80997
Habitat: Mixed forest
Substrate: Resin exudates on a northern white cedar Thuja occidentalis) tree
Collector’s_Name: Alden C. Dirks
Other: I initially thought this was Sarea sp., but looking at the black structures under a dissection microscope they are not apothecia, but perhaps perithecia.

Species Lists


Potential apothecia. Source of ascus-like structures (bitunicate asci?)

Proposed Names

52% (1)
Recognized by sight
41% (2)
Recognized by sight
Based on microscopic features
22% (2)
Recognized by sight
Based on microscopic features
57% (1)
Based on chemical features: ITS rDNA

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= Observer’s choice
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Add Comment
Mixed collection
By: Alden Dirks (aldendirks)
2019-12-06 05:06:18 AEST (+1000)

Containing Sarea difformis, Sarea resinae, and Claussenomyces aff. olivaceus

Best matches with ITS are all members of Tympanidaceae
By: Alden Dirks (aldendirks)
2019-10-31 06:36:26 AEST (+1000)

including Pragmopora, Claussenomyces, and Tympanis, but low query cover and low percent identical.

By: James Mitchell (jkmitchell)
2019-10-10 13:53:32 AEST (+1000)

That is a pretty typical size for North American specimens of Sarea difformis.

Yes, the asci are polysporous, having probably hundreds of spherical spores. For the ascus interior, are you referring to the spores, or the dark small ascus as well? For that one, I am not sure. Could be old, dead, or something else…. As for the pore and dehiscence types, there is a paper here (a bit old, and in French) that discusses these a little bit: The asci should also turn pretty blue in iodine.

And thanks! I look forward to it. Like I said, host family could mean it is different, could not. But it is a rare opportunity to find out!

I’ll get a measurement tomorrow.
By: Alden Dirks (aldendirks)
2019-10-10 13:32:53 AEST (+1000)

My guess is about 500 µm.

The apical pore is very interesting! It looks like the ascus is loaded with spores. Or are those vacuoles? What do you make of the ascus interior?

I’m glad you pushed me to look more at this specimen! I’ll share the ITS data with you when I get it and we can decide what’s the best next step after that.

The apothecia look an awful lot like Sarea
By: James Mitchell (jkmitchell)
2019-10-10 11:57:52 AEST (+1000)

There is a parasite growing on top, and down into the hymenium (not unusual for the collections I have seen), but this looks an awful lot like Sarea. I can see why you thought it was bitunicate, but in Sarea and also in Lecanoromycetes, the ascus tips tend to be very thick and with an apical channel (but not really a pore structure, usually). They can do a pseudo-jack-in-the-box type action, but they are not truly bitunicate. The conidiogenous cells and conidia do not look unlike those of Sarea, as well. Hard to tell the 3D structure in the squash mount, but this is looking very promising.
As for the “lichenization”, it is not uncommon to find algal cells on specimens or near them, but you don’t actually see a close relationship between the algae and the hyphae, just proximity. That is what I am seeing here, I think.
My interest in this specimen has increased by about 100x haha. This (maybe obviously) looks most like Sarea difformis, but that taxon has NEVER been reported forming the teleomorph on any host in Cupressaceae. Might not mean anything, but it might. How big were the apothecia? Or, how tiny rather?

Also, it appears to be lichenized… maybe
By: Alden Dirks (aldendirks)
2019-10-10 11:23:04 AEST (+1000)
Hi James
By: Alden Dirks (aldendirks)
2019-10-10 11:20:00 AEST (+1000)

I took another look at this today. I some fruiting bodies that looked like apothecia. They were very small and difficult to work with, but I think I found asci. I think they are bitunicate asci of Dothideomycetes, but I’m not sure. Any ideas? There were also pycnidia. I was able to see the conidiogenous cells. With my limited knowledge, I don’t think these are Sarea, but definitely ascomycetes, and an interesting habit on Thuja occidentalis resin. I’m working on sequencing my personal collection now, so I’ll keep you in the loop when I get ITS data for this specimen.

Did you look at the specimen more?
By: James Mitchell (jkmitchell)
2019-10-10 07:00:43 AEST (+1000)

Hi Alden,

I was just wondering if you ended up looking at this? They could be pycnidia of a Sarea species, and if so, this is a super rare host (reported only once, over 100 years ago) and I would be interested in borrowing the specimen and sequencing it. Or did they end up being perithecia?