Comparative Morphology of Fruiting Bodies of the Ectomycorrhizal Ammonia Fungus Hebeloma danicum in Serpentine and Neighboring Non‐Serpentine Soils

Serpentine soils are toxic to many plant taxa, resulting in lower plant diversity than in adjacent non‐serpentine soils. Although ammonia fungi are widely distributed in cool and temperate forests, their occurrence and morphological characteristics in serpentine soils remain poorly understood. Preliminary experiments involving urea application in serpentine and non‐serpentine areas showed that the ectomycorrhizal ammonia fungus Hebeloma danicum occurs in both types of soil. Building on these findings, we aimed to compare the morphology of the fruiting bodies of H. danicum in serpentine and non‐serpentine soils. We found that the size and dry weight of H. danicum fruiting bodies from serpentine soils were significantly lower than those from non‐serpentine soils. In addition, morphological analyses showed that the pilei and stipe of the fruiting bodies from serpentine soil were significantly smaller than those from non‐serpentine soil. Notably, this study provides the first evidence of changes in the size of the basidiomata of ectomycorrhizal ammonia fungi in serpentine soils. Overall, our results suggest that fungi exhibit environmentally associated morphological changes, analogous to those observed in reproductive structures in plants.