Researchers discovered two new types of fungi (Nigrospora guangxiensis and N. pubeiensis) living inside agarwood trees in southern China. These fungi, along with two previously known species, were identified using both microscopic observations and genetic analysis. The findings help us better understand which fungi live in agarwood trees and how they might contribute to producing the valuable aromatic resin known as agarwood, which is highly prized in traditional medicine and perfumery.