References
For Apium
Ball, P.W. 2024f. Apium. In Flora of North America Editorial Committee. 2024. Flora of North America north of Mexico. Volume 13, Magnoliophyta: Geraniaceae to Apiaceae. Oxford Univ. Press, New York, NY. 566 pp. Google Scholar
Mathias, M.E., and L. Constance. 1945. Umbelliferae. North American Flora, vol. 28B: 43-397. N.Y. Botanical Garden, New York. Google Scholar
Plunkett, G.M., M.G. Pimenov, J.-P. Reduron, E.V. Kljuykov, B.-E. van Wyck, T.A. Ostroumova, M.J. Henwood, P.M. Tilney, K. Spalik, M.F. Watson, B.-Y. Lee, F.-D. Pu, C.J. Webb, J.M. Hart, A.D. Mitchell, and B. Muckensturm. 2018. Apiaceae. In Kadereit, J., & V. Bittrich. 2018. The families and genera of flowering plants. XV. Flowering plants. Eudicots. Apiales, Gentianales (except Rubiaceae). Springer, Cham. Google Scholar
Ronse, A.C., Z.A. Popper, J.C. Preston, and M.F. Watson. 2010. Taxonomic revision of European Apium L. s.l.: Helosciadium W.D.J. Koch restored. Plant Syst. Evol. 287: 1-17. Google Scholar