Desmodium perplexum is a species of flowering plant in the legume family Fabaceae. It is native to eastern North America. The specific name perplexum refers to the confusion surrounding this species since its initial description in 1950.
Desmodium perplexum is similar in appearance to Desmodium glabellum. The two species remained a source of confusion for botanists until a more reliable identification key became available in 2020. Consequently, much of the information published prior to that date tends to be misleading.