Spotted Knapweed (Centaurea biebersteinii/Centaurea maculosa) Division - Magnoliaphyta Class - Magnoliopsida Subclass - Asteridae Order - Asterales Family - Asteraceae Genus - Centaurea While sporting a beautiful flower, this plant is considered highly invasive and is on the noxious weed list of most of the states it can be found in. The U.S.D.A. labels it Centaurea biebersteinii but most other sources give Centaurea maculosa. Weeds Taxonomic List List by Scientific Name List by Common Name