Publication: Sp. Pl. 2: 987. 1753.
Notes: Split in Kz99, lumped by Chambers and Sundberg (2000).
FNA21: "The name Ambrosia ×helenae Rouleau applies to hybrids between A. artemisiifolia and A. trifida."
WTU specimens on loan, so no specimen data available as of Aug. 2007.