Microtoena affinis is recognized as a distinct species by some taxonomists, whereas others consider it to be closely related to Microtoena delavayi or a form of the latter. No agreement has been reached, and thus the identity of Microtoena affinis and the relationship between the two taxa is unclear. Based on an examination of a large number of herbarium specimens, field observations, scanning electron microscope observations, and statistical analyses of all relevant characters, the name Microtoena affinis is here reduced to a synonym ofMicrotoena delavayi.