| Henricksonia B.L. Turner, 1977 |
| Henricksonia mexicana B.L. Turner, 1977 |
| Hesperevax (A. Gray) A. Gray, 1868 |
| Heteropleura Sch. Bip., 1862 |
| Heteropleura fendleri (Sch. Bip.) Rydb., 1911 |
| Heterosperma Cav., 1794 |
| Heterosperma brandegeei Sherff, 1942 |
| Heterosperma coreocarpoides (Sherff) Sherff, 1942 |
| Heterosperma mexicanum (A. Gray) Lizarazu & S.E. Freire, 2018 |
| Heterosperma mexicanum var. pinnatisectum (S.F. Blake) Lizarazu & S.E. Freire, 2018 |
| Heterosperma pinnatum Cav., 1795 |
| Heterosperma xanti A. Gray, 1861 |
| Heterospermum Willd., 1803 |
| Heterotheca Cass., 1817 |
| Heterotheca arizonica (Semple) G.L. Nesom, 2007 |
| Heterotheca bartlettii (S.F. Blake) M.C. Johnst., 1958 |
| Heterotheca brandegeei (B.L. Rob. & Greenm.) Semple, 1988 |
| Heterotheca chihuahuana (B.L. Turner & S.D. Sundb.) B.L. Turner, 1987 |
| Heterotheca chrysopsidis DC., 1836 |
| Heterotheca fastigiata (Greene) V.L. Harms, 1974 |