Said of hyphae cells containing two nuclei. In Basidiomycota almost all hyphae are binucleate. In Ascomycota binucleate hyphae occur only after fusion of two compatible uninucleate hyphen, as a preamble to sexual reproduction.
A binucleate tissue is called a dikaryon. It is a unique common character of Ascomycota and Basidiomycota, that for this reason are united in the subkingdom Dikarya.