Greenia
| Greenia Nuttall, Trans. Amer. Philos. Soc., ser. 2. 5: 142. 1835, non Wallman 1791. | | TYPE: Greenia arkansana Nuttall = Limnodea L. H. Dewey 1894. |
Sclerachne
| Sclerachne Torrey ex Trinius, Mem. Acad. Imp. Sci. Saint-Pétersbourg, Ser. 6, Sci. Math., Seconde Pt. Sci. 4: 273. 1845, non R. Brown 1838. | | TYPE: Sclerachne arkansana (Nuttall) Torrey ex Trinius (Greenia arkansana Nuttall) Lectotypified by Hitchcock, U.S.D.A. Bull. (1915-1923) 772: 135. 1920. = Greenia Nuttall 1835, non Wallman 1791. = Limnodea L. H. Dewey 1894. |
Thurberia
| Thurberia Bentham, J. Linn. Soc., Bot. 19: 58. 1881, non A. Gray 1854. | | TYPE: Thurberia arkansana (Nuttall) Bentham ex Vasey (Greenia arkansana Nuttall) Proposed as a substitute name for Greenia Nuttall 1835, non Wallman 1791, and for Sclerachne Torrey ex Trinius 1845, non R. Brown 1838. = Limnodea L. H. Dewey 1894. |