Earlier today I found a minute discomycete growing on dying leaves of Galium saxatile on a grassy streambank in the Lake District, NW England. Details as follows:

Apothecia 80-200 µm diam; with a short stalk; grey to pale greenish-blue (dark greenish-blue at the base of the stalk).
Asci 30-40 x 5-7 µm; 8-spored; apex blue in Lugols.
Ascospores fusiform; hyaline; 0-septate; 9-11 x 2-2.5 µm; 2 large oil bodies.
Paraphyses sparse; narrowly cylindrical; about as long as asci.
Hairs more or less cylindrical or slightly tapering to rounded apex; <40-45 x 2-3 µm; verruculose.

Some images attached.

I rarely look at discomycetes and I'm struggling to put a name to this specimen. Possibly a Cistella? I'd be grateful for any help anyone can provide.

Thanks
Marcus

Hans-Otto Baral, 19-05-2022 22:15

Re : Cistella (?) on dying leaves of Galium saxatile

oh my dear, I do not know. Such bluegreen colour is meaningful. I don't think in a Cistella. A Hyphodiscus perhaps? But on that substrate?

How large were the apos, and were they sessile? You doi't habe a macro?

Probably a sparse record?

The ectal excipulum gelatinized?

Hans-Otto Baral, 19-05-2022 22:45

Re : Cistella (?) on dying leaves of Galium saxatile

My database says that Boudier described a Trichopeziza galii. But that was on stems, was probably not greenish, and is said to be C. grevillei.

Kosonen Timo, 20-05-2022 07:48

Re : Cistella (?) on dying leaves of Galium saxatile

Very interesting!

What about Incrupila? -Then again, verrucose is not = thick crystalline crust on the hairs and hairs seem aseptate here as well. Green-blue colours certainly a rare character. Somewhere around Cistella or Hyphodiscus would be my guess (too). It doesnt look like a Hyaloscyphaceae (s str) or Lachnaceae (s lat), --kind of too fragile (?) for the latter. 

Timo

Lothar Krieglsteiner, 20-05-2022 09:40

Re : Cistella (?) on dying leaves of Galium saxatile

what about Chlorociboria aeruginella?

Hans-Otto Baral, 20-05-2022 10:02

Re : Cistella (?) on dying leaves of Galium saxatile

I thought this also but I remembered the spores with smaller LBs and the hairs smooth. The latter isn't true, there can in fact be a rough deposit on them. So it seems you are right, Lothar!

Lothar Krieglsteiner, 20-05-2022 10:35

likely Chlorociboria aeruginella (s.l.?)

I found this species only once in my life, although I repeatedly saw blue-green stains on herbaceous plants including Filipendula that could have been caused by this species. Surely it is no Chlorociboria ...

• Chlorociboria.-Boletus-2002-0002.pdf

Hans-Otto Baral, 20-05-2022 10:43

Re : Cistella (?) on dying leaves of Galium saxatile

But it is a Chlorociboriaceae, related to the lignicolous Chlorociboria halonata and "Hyphodiscus chlorociborioides".

Lothar Krieglsteiner, 20-05-2022 14:58

Re : Cistella (?) on dying leaves of Galium saxatile

vielen Dank, Zotto!