I found this Nectria species, which belongs to the N. cinnabarina complex. The dark colour was remarkable for me. Analyzing the spores I found several of it with three septa. So I thought this was N. cinnabarina s. str. But after further search I also found two spores with four septa. According to the key of Hirooka, Rossman and Chaverri: "A morphological and phylogenetic revision of the Nectria cinnabarina species complex" this is Nectria nigrescens.

The name suggests a blackening behavior of the species. But this is not described for this species. The normal colours are brighter like in N. cinnabarina but all species, including N. dematiosa can be more or less darker. The dried sporodochia seem to be darker than the fresh ones. Some of them are black now.

Am I right with N. nigrescens? Are there new scientific findings? Is this a rare or overlooked species?

Sporodochia: short stipitate to sessile, dark red brown, seem to blacken when dried
Ascospores: 12-16 (19) x 4-5,5 µm, mostly 1, sometimes 0 or 2 septate, rarely 3 septate

Best regards
Steffen

Norbert Heine, 17-03-2021 11:37

Re : Nectria nigrescens?

Hallo Steffen,

ergänzend zu Irmgards Ausführungen siehe auch den Beitrag von Matthias im Pilzforum.eu von 2019.

https://www.pilzforum.eu/board/thread/42829-nectria-cinnabarina-genau-betrachtet/

Viele Grüße, Norbert