Discomycete ID confirmation please

[Chris Yeates]

hello all

Andreas' interesting puzzle has inspired me to get to work on something I noticed last week on the underside of a rotten and sodden oak branch

it's a discomycete around 0.2mm in diameter, and the first thing I observed in the field under a x15 lens was lots of dark 'bristles' tipped with shining globules; these I recognised as a 'hyphomycete' and so collected part of the affected wood, as I'm interested in the group and very few British mycologists look at them:


I must stress here that I am not looking at the (relatively massive) Mollisia species, but the band of 'glistening globules' running across the middle of the photograph; a closer look revealed the much smaller (and hairy) disco's (arrowed here), which seemed to be growing only where the globules were also present:


a closer look (sorry about the quality of the image but these are very small):


under the microscope the assumed connection between the hyphomycete and the discomycete appeared to be confirmed:


each tip of the black bristles opened into a brush-like bundle of asexual spore-bearing cells:


I could not see any mature spores outside the asci which I could definitely say were ascospores and not conidia (asexual spores), but those inside the ripe asci were around 6-7 microns long x 2-3 microns wide, and the hairs were characteristic with numerous resin-like encrustations:


I remembered reading about the importance of these when identifying Hyaloscypha species in a paper by Huhtinen, and this led me to the family Hyaloscyphaceae and the reasonably confident identification of Dematioscypha dematiicola growing with its Haplographium 'imperfect' state; I have not seen this before and have not come across a mention of the resinous bodies on the hairs however, and in the very closely related genus Hyaloscypha these appear to be of taxonomic importance

I would welcome any comments (other than the obvious "why the hell do you look at such things" )

cheers

Chris

[mollisia]

Hello Chris,

those resinous exudates in Dematioscypha are known to me only from Dematioscypha richonis (Vel.) Huhtinen. I have never found them on D. dematiicola. Usually they are red, but there is a var. olivacea with green exudates.

There is a microscetch in the Internet, drawn by Stip Helman (whom I know personally, he's a good guy in Hyaloscyphaceae really!) on his internet site www. helotiales.nl (I hope this hint is allowed as it is no direct link).

I'm not sure about the identity of your collection, because I have never found that Dematioscypha richonis myself and I don't have the publication HUHTINEN 1987 at hand at the moment. But may be it's a hint to search for.

best regards,
Andreas

[Chris Yeates]

hello Andreas

I am so glad I posted this, and thanks for the suggestion of Dematioscypha richonis - In Dennis's 1949 booklet on British Hyaloscyphaceae . . . he includes richonis (clearly the nominate variety as he calls the oil droplets 'red', interestingly he doesn't mention the presence of an anamorph) on the basis of a single collection from Yorkshire in 1900 - there appears to have been only one further British collection of this variety); the var. olivacea, which seems closer to my collection does not have a localised record and is merely included on FRDBI because it was included in the 1985 Ascomycotina Checklist

without your comments this would have been packeted and filed away as probably Dematioscypha dematiicola

I shall email Stip Helleman and ask for his comments, and then the material will go to Kew for Brian to pore over

best wishes

Chris

[Chris Yeates]

hello Andreas

Stip has kindly got back to me and (well done you) it is one of the richonis segregates

apparently the chief distinction now is whether there are croziers present (I am a bit surprised that such a feature only serves to distinguish varieties but perhaps richonis and olivacea will eventually merit separation at a higher level)

I don't wish to pester Stip too much (at this stage ), so how do I go about searching for croziers? . . . is there a preferred stain? etc. I understand the general principles, but this is something I haven't really got into before

exciting!

best

Chris

[mollisia]

Originally Posted by Chris Yeates

I don't wish to pester Stip too much (at this stage ), so how do I go about searching for croziers? . . . is there a preferred stain? etc. I understand the general principles, but this is something I haven't really got into before

Hallo Chris,

the taxonomic value of the croziers is unfortunately not very well known. But there are several cases where this feature is distinctive between closely related species which are not so easy to separate in their other characters. You have certainly realized the importance of this character e.g. in the Hyaloscypha monograph of HUHTINEN, and further examples of such pairs are:
Mollisia rosae vs. Mollisia prunicola
Heyderia pusilla vs. Heyderia abietis
Lachnum caricis vs. Lachnum sesleriae
Dasyscyphella crystallina vs. Dasyscyphella nivea
Microglossum viride vs. Microglossum olivaceum
Hymenoscyphus scutulata vs. Hymenoscyphus fucatus
(always the first species is without croziers, the 2nd with croziers)

The best to search for croziers is in living material mounted in tap water. Take a bit of the hymenium and press only slightly. It is important not to press too much. Just enough to get the structures apart, but not so much that you kill the cells by pressure.
From herbarium material it is often a matter of patience until you find a place on the preparation that has the asci separated enough to show the bases, but not pressed as much that they get separated from the basal cells. Staining with congo red or L4T (trypan blue in L4) helps in herbarium material. And you should mount the preparation in KOH, then wash it with water, then stain with congo red for a minute, and then mount in water again for observation.
Sometimes you don't succeed in seeing croziers for sure. In some cases the form of the free ascus base may give a hint on having had croziers or not. The bases which were connected by croziers are not straight but have a slight ancle in many cases. But it is only a good hint when you see the ancled base. The strait base can occure in both versions and is therefore without significance.

Two examples of an ascus base showing the ancle:





best regards,
Andreas

[Chris Yeates]

hello Andreas (and indeed all WABbers . . . )

very many thanks for your advice; Stip Helleman has also been very helpful and has confirmed (from photos I sent him of asci in Congo Red) that it does not have croziers and is therefore Dematioscypha richonis var. olivacea;I had suspected this would be the case from the lack of pinkish/reddish coloration of the 'resin' on the hairs

I cannot find a localised GB record for this . . . British Fungi - record details . . . so a nice find (though clearly overlooked!)

out today and found this fellow again:


have you found Heteromycophaga yet?

best wishes

Chris

[oxycera]

now this is what I call a thread - even if I don't understand a word of it

[mollisia]

Originally Posted by Chris Yeates

have you found Heteromycophaga yet?

Hello Chris,

no I haven't
But we found a very rich spot of Exidia glandulosa (just opposit of the forest with the Eranthis), were many stems are densly covered on two to three meters length. They are all young and fresh, but in a week or so they get older - and hopefully parasized

best regards,
Andreas

[Chris Yeates]

Originally Posted by oxycera

now this is what I call a thread - even if I don't understand a word of it

I don't believe you . . . mycologists and entomologists work in rather similar ways - imagine a discussion referring to genitalia, wing venation and leg bristles

same difference

Chris

[oxycera]

It's great you've been able to tap into such expertise to match your own.
I'm tempted to post some of my unknown moss pics - you just don't know who's out there!