Scientists from Royal Botanic Gardens Victoria and collaborators have formally described a curious new Australian mushroom species that combines bright yellow colouring with a powerful mothball smell. 

The newly named Hodophilus citrinofoetens was identified through the examination of Australian fungal collections and DNA analysis. The rare species is currently found in only a handful of locations in Tasmania and the south-west of Western Australia.  

Lead author Luke Vaughan, Research Assistant (Taxonomic Mycology) at Royal Botanic Gardens Victoria, said the unusual species immediately stood out from its relatives. 

"Most species in this group are shades of brown, so the vivid yellow sporing bodies and distinctive mothball smell of this species is quite unique." 

"There are many remarkable fungi waiting to be documented, even among collections that have been sitting in fungaria for years." 

Researchers found the mushroom is unique among known members of the genus. While some related species have strong naphthalene or mothball-like odours, they are generally brown. Species with yellow colouring typically lack the distinctive smell. Hodophilus citrinofoetens combines both characteristics.  

The research, published in the Australian Journal of Taxonomy, emerged from a broader investigation into the diversity of Hodophilus in Australia, which uncovered evidence that at least six additional species await formal naming.  

Royal Botanic Gardens Victoria scientist Dr Gareth Holmes said the findings show the value of DNA sequencing for studying Australia's fungal diversity.” 

"When we combined DNA sequencing with specimens collected across Australia over many decades, we uncovered a much bigger story than a single new species." 

"The results suggest there are numerous Australian fungi that have not yet been formally recognised by science." 

The study also clarified the classification of two previously known Australian species, confirming they belong within the genus Hodophilus and renaming them Hodophilus darwinensis and H. kearneyi.  

The researchers say the findings highlight the importance of fungal collections, field surveys and modern genetic techniques in building a clearer picture of Australia's biodiversity. 

Dr Tom May, Principal Research Scientist at Royal Botanic Gardens Victoria, said understanding what species exist is fundamental to protecting them. 

"You can't conserve biodiversity if you don't know what's there." 

"We know that Australia's fungal diversity is still far from fully documented, and every new species we formally recognise helps us better understand the ecosystems that support life across the continent."