Hi Nina

the presense of VBs in paraphyses/hairs excludes a Dennisiodiscus. lacking croziers and such spores remind me of Mollisia retincola, a species with a distinct yellow KOH-reaction adn particularly with abundant crystals in the medulla. I am not sure if you have any crystals there?

But the apos are extraordinarily large!

Zotto

Thank you, Zotto.

The crystals present, they are in clusters and when the mount tapped they appear in abundance. I looked at your specimens of M. retincola. The habitat looks the same. But Mollisia is superficial and sited at subiculum. This specimen emergent, e.g. there is clear hole in the epidermis when the frb scraped from it. It is seen at picture of section (dark patch of  leaf epidermis at base, and central part of frb going into the leaf).

I also had not described green content (oil) of paraphyses, this may be important. It is clear seen only in apos with green hymenium. Oil is colored blue in TB. And KOH dissolves all oil content (have not seen change to yellow, but it is dead stuff).

I don't mind with erumpent apothecia, though this is an interesting observation. For the delimitation from Pyrenopeziza this character is quite obsolete, though a tendency is visible. The VBs in the paraphyses clearly place this in Mollisia. Your test with KOH sounds reasonable (I assume you observed immediately when the KOH reaches them), no problem with herbarium material just if you still see them so clearly.

I have a folder "subretincola KOH-" which means that this is a species complex. Typical M. retincola I only know from Phragmites, whereas this one with KOH- is on Cyperaceae, so probably a different species with a deviating ecology.

VBs are recognized by their turquoise stain in CRB, oil drops do not stain. So I think your spore photo shows no clear blue of the drops, more a general colour effect.

I agree, now having watched "subretincola" folder i see that there most similarities with mine except attachement. Your collection 6410 also from Carex rostrata, and other characters coinside. I have not seen in yours brown exudates in medulla of receptacle, which makes mottled patterrn at section in mine. But the structure of excipulum seems variable in all these specimens, part of them without flank hairs as well.

I was following the dissolving of VBs in paraphyses now to be sure there is no change in color; and no, it has not showed up.

Oil in spores, of course, not blueing - now i hope i have learned this. Thanks for your instructions!

I think it is this perhaps undescribed species. You have very large apos, so they surely have an advanced age, and maybe the excipulum darkens with age.