Iva L.
As currently circumscribed Iva comprises nine species, mostly native to temperate North America (Mabberley 2008). Recent molecular phylogenetic research supports the segregation of Cyclachaena Fresen. (with the noxious agricultural weed C. xanthiifolia (Nutt.) Fresen.; syn. Iva xanthiifolia Nutt.) from Iva (Karis 1995, Miao & al. 1995a, b).
References
Jackson R.C. (1960) A revision of the genus Iva. Univ. Kansas Sci. Bull. 41: 793-876.
Karis P.O. (1995) Cladistics of the subtribe Ambrosiinae (Asteraceae: Heliantheae). Syst. Bot. 20: 40-54.
Mabberley D.J. (2008) Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge: XVIII + 1021 p.
Miao B.M., Turner B.L. &Mabry T.J. (1995a) Systematic implications of chloroplast DNA variation in the subtribe Ambrosiinae (Asteraceae: Heliantheae). Amer. J. Bot. 82: 924-932.
Miao B.M., Turner B.L. &Mabry T.J. (1995b) Molecular phylogeny of Iva (Asteraceae: Heliantheae) based on chloroplast DNA restriction site variation. Pl. Syst. Evol. 195: 1-12.
Pruski J.F. (2005) Nomenclatural notes on Cyclachaena (Compositae: Heliantheae), resurrection and lectotypification of Iva sect. Picrotus, and report of Iva (syn. Cyclachaena) as new to Armenia. Compositae Newsl. 42: 32-42. [available online at: http://uqu.edu.sa/files2/tiny_mce/plugins/filemanager/files/4281685/No;%2042.pdf].
Strother J.L. (2006) Iva. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 21. Oxford University Press, New York-Oxford: 25-28.