Ptilimnium is a group of plants in the family Apiaceae described as a genus in 1819.Rafinesque, Constantine Samuel. 1819 American Monthly Magazine 4: 192Tropicos, Ptilimnium Raf. The common name is mock bishopweed or mock bishop's weed. It is endemic to the United States, primarily in the Southeast, the Lower Mississippi Valley, and the Lower Great Plains.Biota of North America Program 2013 county distribution maps
Species , Plants of the World Online accepted five species: Ptilimnium ahlesii Weakley & G.L.Nesom Ptilimnium capillaceum (Michx.) Raf. - SE + SC + NE USA Ptilimnium costatum (Elliott) Raf. - SC USA Ptilimnium nuttallii (DC.) Britton - SC USA Ptilimnium texense J.M. Coult. & Rose - Texas, Louisiana, Florida
Ptilimnium nodosum (Rose) Mathias, native to Georgia and South Carolina, is treated as Harperella nodosa by Plants of the World Online.
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