Synonyms recognized by ITIS (bold taxon is currently accepted):

     Ambrosia trifida L.

Common Name(s): blood ragweed, giant ragweed, great ragweed, horseweed, perennial ragweed (great), tall ragweed.

Taxonomic Hierarchy: (ITIS TSN=36521, click for more information and references)

        Kingdom: Plantae
            Subkingdom: Tracheobionta
                Division: Magnoliophyta
                    Class: Magnoliopsida
                        Subclass: Asteridae
                            Order: Asterales
                                Family: Asteraceae
                                    Genus: Ambrosia
                                        Species: Ambrosia trifida