For Lythrum
Graham In Kubitzki, K., C. Bayer, and P.F. Stevens, eds. 2007. The families and genera of vascular plants. IX. Flowering plants – Eudicots – Berberidopsidales, Buxales, Crossosomatales, Fabales p.p., Geraniales, Gunnerales, Myrtales p.p., Proteales, Saxifragales, Vitales, Zygophyllales, Clusiaceae alliance, Passifloraceae alliance, Dilleniaceae, Huaceae, Picramniaceae, Sabiaceae. Springer, Berlin. 509 pp.
Graham, S.A. 1975. Taxonomy of the Lythraceae in the southeastern United States. Sida 6: 80-103.
Graham, S.A. 2021g. Lythrum. In Flora of North America Editorial Committee. 2021. Flora of North America north of Mexico. Volume 10, Magnoliophyta: Proteaceae to Elaeagnaceae. Oxford Univ. Press, New York, NY. 456 pp.
Haines, A.A. 2010. New combinations in the New England tracheophyte flora. Stantec Botanical Notes 13: 1-8. [and 1 page addendum]