Trogia venenata (Agaricales), a novel poisonous species which has caused hundreds of deaths in southwestern China

About 400 unexplained sudden deaths have occurred in Yunnan Province in southwestern China during summers over the last 35 years. Extensive field investigations revealed that a fungus called little white mushroom or nail-like mushroom by the local people could be one of the chief causes. Fieldwork showed that this fungus is a common saprophytic species growing on rotten wood in southwestern, central, and northwestern Yunnan in subtropical mountainous areas between 1,700 and 3,000 m altitude. Morphological and molecular phylogenetic analyses revealed that it is a new species of the genus Trogia, closely related to the palaeotropical T. infundibuliformis and its allies. Accordingly, T. venenata is described and illustrated.