References

For Zizia

Cooperrider, T.S. 1985. Thaspium and Zizia in Ohio. Castanea 50: 116-119. Google Scholar

Levin, G.L. 2024e. Zizia. 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