2011: one fungus gets one name

At the XVIII International Botanical Congress in Melbourne in July 2011, the nomenclature section adopted a series of changes concerning fungi. The most widely recognised became the principle of "one fungus, one name". Previously the code had allowed the sexually and asexually reproducing stages of the same fungus to carry separate formal names. That arrangement arose at a time when different forms could not reliably be connected into a single life cycle.

Culturing, microscopy and later DNA data increasingly showed that two names referred to a single organism. Maintaining parallel systems hampered communication in medicine, plant protection, ecology and databases. Melbourne did not, however, automatically choose one list of winning names. The change set in motion the work of committees, which had to weigh priority, prevalence of use and the stability of nomenclature within particular groups.

The congress also widened the code's title, explicitly placing algae, fungi and plants in it, permitted effective electronic publication, and allowed descriptions in English alongside Latin. Some of the rules took effect from 1 January 2012. For new fungal names, registration in a recognised repository became essential. Publishing a taxon ceased to be solely a matter of a printed diagnosis scattered through a journal.

The reform did not remove synonyms or taxonomic disputes. One nomenclatural name does not mean one unchanging hypothesis about the boundaries of a species. Research may still merge or divide taxa, and old names remain necessary when searching the literature. The significance of the decision lay in bringing the rules into line with the biological identity of the organism and with the digital circulation of knowledge.

What the Melbourne Code actually changed

Before the reform, one fungus could carry separate Code-compliant names for its asexual morph (anamorph) and sexual morph (teleomorph). The decision taken in Melbourne in July 2011 ended that exception from 1 January 2013: every legitimately published fungal name could compete for priority regardless of the life stage represented by its type. Older anamorph- and teleomorph-based names were not automatically made illegitimate; protected and rejected lists were envisaged to reduce disruptive name changes.

The same reform introduced another practical threshold. A new fungal name published from 1 January 2013 without a unique identifier issued by a recognized repository is not validly published for nomenclatural purposes. The Congress therefore did not rename every fungus overnight. It supplied rules for choosing among competing names and required a persistent digital registration trail for future novelties.