Cyclachaena Fresen.
Cyclachaena is a monospecific genus, native to North America. It was included for a long time in Iva but molecular phylogenetic research supports its separation from the latter (see for instance Karis 1995; Miao & al. 1995a,b; Mabberley 2008).
Literature:
Jackson R.C. (1960) A revision of the genus Iva L. Kansas Uni. 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. (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://www.biodiversitylibrary.org/item/48871#page/1/mode/1up].
Strother J.L. (2006) Cyclachaena. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 21. Oxford University Press, New York-Oxford: 28.