Abstract
Exact data on vegetation and habitat conditions of selected Czech and French localities of a rare sphagnicolous fungus Pholiota henningsii (Agaricales, Strophariaceae) are published. The habitats are characterized phytosociologically and are supplemented with published data on their Holocene history.
The case study is supplemented with an annotated list of other European localities. Generally, the fungus occurs in spring fens, transitional mires and raised bogs at the altitude of 25-1930 m, both nutrient-rich to oligotrophic and calcareous to acidic.
It is confined to areas having a long-term continuity of the forest/treeless mire mosaic, that are palaeorefugia of the relict Holocene habitats. Most localities are situated in the vicinity of the open water bodies, such as lakes, ponds, mire-pools, rivers and seas; thus, they are influenced by ground water or evaporation from the water bodies.
If not, their humidity is caused by rich precipitations in (sub-)oceanic regions or foothills of mountains, humid mesoclimate in wooded areas or direct cover of shrubs and trees keeping a humid microclimate. The species resists quite well to disturbances, on condition that the water balance is untouched.