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Lichen white perithecia ?

Verfasst: Mo Nov 20, 2023 2:16 pm
von BubikolRamios
Was not in focus of my attention, so this is best photo I can pull. Slovenia, Karst, Church wall.
Around other 'same brown' spots with fewer(and opt. even smaller) to no white specks. ... 683193c4be

Re: Lichen white perithecia ?

Verfasst: Mo Nov 20, 2023 8:57 pm
von abeja
I have never seen this and have no idea.
But I think, those brighter spots are no perithecia (which are black), but something like soredia (asexual propagation).
So we are looking for a brownish lichen growing on stone, with a crustose thallus without marginal lobes, with soredia (or similar).

I tried some Italian keys from the beginning.
"Playing" with the key for Northern Italy (tried the Karst key as well, because of Slovenia mentioned, but no matching results) ... key_id=241
Only ticking what I believe to see or what I know, guessing "photobiont trentepohlioid" (yellow-brown colour), ignoring the chemical reactions, 7 species remaining --> textual key to remaining taxa

Within these results Enterographa zonata looks very similar ... but only some pictures, especially the second one. ... ge&id=2211

Another description: ... pha-zonata

Re: Lichen white perithecia ?

Verfasst: Di Nov 21, 2023 8:47 pm
von BubikolRamios

A bit off topic: ... oratum.htm

down there man says: "Ostiole are under surface of stroma, obviously surrounded with ring of white stuff".
Does not say what that white stuff is.

Re: Lichen white perithecia ?

Verfasst: Di Nov 21, 2023 9:43 pm
von abeja
Yes, this is a Hypoxylon species (not a lichen), there are perithecia here. When mature, you can see an opening (ostiole) from above and also a certain structure in the section (macroscopically already, better microscopically of course). Whether or how the perithecia are embedded in the stroma and whether there is a colour-contrasting area around the opening is also relevant.
I remember something like this because I once had (immature) Hypoxylon ticinense or subticinense, which would have differed macroscopically in this respect ... I'm always looking for something like that. Unfortunately, the fruiting bodies died before they were ripe (without visible perithecia and without white or black areas around them).
The descriptions of Hypoxylon always say "white substance" - I think it is only pigmented material, without any special function for reproduction. The white substance will not be spreaded - in contrast to the whitish appearing soredia in lichens.
For comparison: ... inense.htm ... inense.htm