References

For Helanthium

Haynes, R.R., and C.B. Hellquist. 2000a. Alismataceae. In Flora of North America Editorial Committee. 2000. Flora of North America north of Mexico. Volume 22, Magnoliophyta: Alismatidae, Arecidae, Commelinidae (in part), and Zingiberidae. Oxford Univ. Press, New York, NY. 352 pp. Google Scholar

Haynes, R.R., D.H. Les, and L.B. Holm-Nielsen. 1998a. Alismataceae. Pp. 11-18. In Kubitzki, K., ed. 1998b. The families and genera of vascular plants. IV. Flowering plants – Monocotyledons – Alismatanae and Commelinanae (except Gramineae). Springer, Berlin. 511 pp. Google Scholar

Lehtonen, S., and L. Myllys. 2008. Cladistic analysis of Echinodorus (Alismataceae): simultaneous analysis of molecular and morphological data. Cladistics 24: 218-239. Google Scholar

Ungberg, E.A. 2022. New and notable vascular plant records from North Carolina. Pp. 406-414 in In Weakley, A.S., D.B. Poindexter, B.A. Sorrie, E.A. Ungberg, S.G. Ward, J.W. Horn, W.M. Knapp, and S.P. Grund. 2022. Studies in the vascular flora of the southeastern United States. VIII. J. Bot. Res. Inst. Texas 16(2): 377-418. Google Scholar