Ambrosia rugelii
| Ambrosia rugelii Rydberg, in Britton, N. Amer. Fl. 33: 19. 1922. | | TYPE: FLORIDA: Without data, Rugel 508 (holotype: NY). |
Ambrosia californica
| Ambrosia californica Rydberg, in Britton, N. Amer. Fl. 33: 20. 1922. | | TYPE: CALIFORNIA: Santa Barbara Co.: Santa Barbara, 1865, Torrey 226 (holotype: NY). |
Ambrosia coronopifolia
| Ambrosia coronopifolia Torrey & A. Gray, Fl. N. Amer. 2: 291. 1842. | BASIONYM: Ambrosia hispida Torrey 1828, non Pursh 1814. | |
Ambrosia coronopifolia var. asperula
| Ambrosia coronopifolia Torrey & A. Gray, var. asperula A. Gray, Boston J. Nat. Hist. 6: 226. 1857. | | |
Ambrosia coronopifolia var. gracilis
| Ambrosia coronopifolia Torrey & A. Gray, var. gracilis A. Gray, Boston J. Nat. Hist. 6: 227. 1857. | | |
Ambrosia hispida
| Ambrosia hispida Torrey, Ann. Lyceum Nat. Hist. New York 2: 216. 1828, non Pursh 1814. | | TYPE: ILLINOIS: Without data, Short s.n. (holotype: NY). |
Ambrosia lindheimeriana
| Ambrosia lindheimeriana Scheele, Linnaea 22: 156. 1849. | | TYPE: TEXAS: |
Ambrosia psilostachya var. californica
| Ambrosia psilostachya de Candolle, var. californica (Rydberg) S. F. Blake, in Tidestrom, Fl. Utah 580. 1925. | BASIONYM: Ambrosia californica Rydberg 1922. | |
Ambrosia psilostachya var. coronopifolia
| Ambrosia psilostachya de Candolle, var. coronopifolia (Torrey & A. Gray) Farwell ex Fernald, in A. Gray, Manual, ed. 8. 1470. 1950. | BASIONYM: Ambrosia coronopifolia Torrey & A. Gray 1842; Ambrosia hispida Torrey 1828, non Pursh 1814. | |
Ambrosia psilostachya var. lindheimeriana
| Ambrosia psilostachya de Candolle, var. lindheimeriana (Scheele) Blankinship, Rep. (Annual) Missouri Bot. Gard. 18: 173. 1907. | BASIONYM: Ambrosia lindheimeriana Scheele 1849. | |