| Hesperaloe nocturna Gentry, 1967 |
| Hesperaloe parviflora (Torr.) Coult., 1894 |
| Hesperaloe parviflora subsp. parviflora (Torr.) Coult., 1894 |
| Hesperaloe tenuifolia G.D. Starr, 1997 |
| Hesperaloe yuccifolia (A. Gray) Engelm., 1871 |
| Hesperocallis A. Gray, 1868 |
| Hesperocallis undulata A. Gray, 1867 |
| Hesperoyucca (Engelm.) Baker, 1892 |
| Hesperoyucca newberryi (McKelvey) Clary, 2001 |
| Hesperoyucca peninsularis (McKelvey) Clary, 2001 |
| Hesperoyucca whipplei (Torr.) Baker, 1892 |
| Heteracanthae Salm-Dyck, 1861 |
| Hibernicae Hochstätter, 2015 |
| Hiemiflorae Hochstätter, 2015 |
| Hyacintheae Dumort., 1827 |
| Hyacinthinae Parl., 1852 |
| Hyacinthus L., 1753 |
| Hyacinthus orientalis L., 1753 |
| Inermes Salm-Dyck, 1861 |
| Intermediae R.H. Webb & G.D. Starr, 2015 |