Dirt or type? Clarifying fungal nomenclature in the DNA age.

The rapid expansion of high-throughput sequencing and environmental DNA (eDNA) studies has led to the introduction of dozens of fungal names based exclusively on molecular data derived from environmental substrates such as soil, dung, or water. In several recent cases, authors and nomenclatural repositories have divergently treated such names as valid or invalid on the grounds that the designated types may or may not constitute specimens under the current wording of the International Code of Nomenclature for algae, fungi, and plants (ICN; Madrid Code). Here, we examine the nomenclatural basis of these treatments by analysing the relevant ICN provisions on specimens, gatherings, admixtures, and typification. We show that while a conservative curatorial approach is defensible under current practice and aligned with the ICN's objective of nomenclatural stability, the Code does not explicitly address whether preserved environmental samples can serve as types when a taxon is evidenced solely by a molecular signal. We therefore argue that explicit clarification-through formal proposals to amend Chapter F and/or relevant general ICN provisions-is now urgently required to ensure consistent, transparent, and future-ready nomenclatural practice in the face of accelerating detection-driven discovery. Graphical Abstract.