Marasmiellus maas-geesterani

This is a rare and little-known species that was not described until the year 2000 by Robich and Campo.

Its pileus, up to 3 cm in diameter, is cream- or flesh-colored, fading in dry weather. The stipe, of similar dimensions to the pileus, is slightly paler in its upper part, while in the lower part it becomes a dark, rooting extension buried in the soil.

Marasmiellus carneopallidus shares habitat and macroscopic appearance, but differs in the morphology of its caulocystidia and cheilocystidia.

The first time I observed this elusive species was in May 2016, in a cattle-grazed meadow in the locality of Orduña (Bizkaia). At the time of collection I was unable to determine its identity, and it was thanks to Ricardo Ibarretxe's microscopic study that we identified it.

Despite returning to the site several times, I was unable to find it again.

It was not until the spring of 2024 that I encountered it again, this time in the Badaia mountain range (Álava), also on calcareous soil in a heavily grazed pasture. On this occasion, by unearthing the specimens, I was able to observe them growing on undetermined herbaceous remains.

These two records represent the only known citations for the Iberian Peninsula.