On the Typification of Ganoderma sichuanense (Agaricomycetes)-the Widely Cultivated Lingzhi Medicinal Mushroom

The well-known and widely cultivated lingzhi has had a significant impact on Chinese culture and is now an important fungal crop providing medicinal benefits to human health and economic value to social development within China and around the world. The European mushroom name, Ganoderma lucidum, has been misapplied to this species for over 100 years until recently reidentified as G. sichuanense. Soon after this, a new species name, G. lingzhi, was also proposed for the fungus because of an unusual internal transcribed spacer (ITS) sequence purportedly of the holotype of G. sichuanense. This extraordinary ITS sequence, which apparently belongs to another species, created an inconsistency between morphological characteristics and molecular data of the holotype making it "demonstrably ambiguous"; this led to an epitypification to support the holotype for the precise application of the name, according to the International Code of Nomenclature for algae, fungi, and plants. However, arguments concerning the names G. sichuanense and G. lingzhi are still heating up, including attempts to reject the epitype of G. sichuanense. To clarify the confusion, the typification of G. sichuanense is reviewed here to demonstrate that the epitype of G. sichuanense was appropriately designated for the purpose to support the holotype of the name, the fact that both G. sichuanense and G. lingzhi are conspecific, and that the name G. lingzhi was based on the unwarranted ITS sequence claimed to be of the holotype of G. sichuanense. Suggestions are made for this case to make a way forward, especially re-examination of relevant fungarium collections to reach a consensus to stabilize the use of the name.