Kew mycologists Bryn Dentinger and Laura Martinez-Suz have discovered three species of mushrooms that are new to science in a commercial packet of dried Chinese porcini purchased from a shop in London.

Porcini mushrooms (Boletus section Boletus) are one of the most traded wild edible mushrooms, but although relatively well known, recent research at Kew has shown that they are more diverse than previously thought. China is a major exporter of porcini, mainly to Europe, but reliable identification of wild collected porcini can be difficult, especially from under-documented regions.

Although it had been shown previously that unknown species were entering the porcini trade, even the Kew mycologists were surprised when they used DNA-sequencing methods to identify 15 mushroom pieces from the commercial packet and found that all belonged to three diagnosable species, none of which had scientific names.

The finding demonstrates the ubiquity of unknown fungal diversity, even in traded products, and the recognition of these species will enable better regulations to improve food safety and enable countries to adhere to international agreements on the exploitation of wild species.