Identification request for Icelandic brown-mushrooms

[Jóhannes]

Found these two mushrooms in a field - close to pine- and birch trees and separate from each other.

Identification app gives different result every time I try to identify, some lethal outcomes and some edible ones and some that cause hallucinations.

Most common the "Split Fibrecap", also known as Inocybe Fastiagiata.

Thanks in advance!

[Dave W]

It's a species of a genus housed in Family Inocybaceae  http://inocybaceae.org/ . Up until recently, there was one genus, Inocybe. An effort headed by American mycologist Brandon Matheny proposes that Inocybe be split apart into several genera, as seen in the linked article.

Regarding the specific mushroom pictured, it looks like what had been called Inocybe fastigiata in old field guides (North American). According to Index Fungorum, the old species name Inocybe fastigiata in a modern context refers to any of 34 different taxa! http://www.indexfungorum.org/Names/Names.asp . All but two of these (relatively) newly named species are now housed in genus Pseudosperma. Two species are placed into genus Inosperma. None of the current species names is "fastigiata"! 

I can say from experience that these little guys with the shiny caps that tear apart radially as they mature are a tricky group. On my own 4 acre property here in Pennsylvania USA I have collected at least two different species that look pretty much like the mushrooms seen here. How did I know the species were different? The shapes of the spores were not the slightest bit similar. 

[Jóhannes]

16 hours ago, Dave W said:

It's a species of a genus housed in Family Inocybaceae  http://inocybaceae.org/ . Up until recently, there was one genus, Inocybe. An effort headed by American mycologist Brandon Matheny proposes that Inocybe be split apart into several genera, as seen in the linked article.

Regarding the specific mushroom pictured, it looks like what had been called Inocybe fastigiata in old field guides (North American). According to Index Fungorum, the old species name Inocybe fastigiata in a modern context refers to any of 34 different taxa! http://www.indexfungorum.org/Names/Names.asp . All but two of these (relatively) newly named species are now housed in genus Pseudosperma. Two species are placed into genus Inosperma. None of the current species names is "fastigiata"! 

I can say from experience that these little guys with the shiny caps that tear apart radially as they mature are a tricky group. On my own 4 acre property here in Pennsylvania USA I have collected at least two different species that look pretty much like the mushrooms seen here. How did I know the species were different? The shapes of the spores were not the slightest bit similar. 

Thank you very much for this extensive response- it has been very helpful and educational!