| Fendlerella queretarana B.L. Turner, 2013 |
| Fendlerella utahensis (S. Watson) A. Heller, 1898 |
| Hortensia Comm. ex Juss., 1789 |
| Hortensia opuloides Lam., 1789 |
| Hydrangea L., 1753 |
| Hydrangea albostellata Samain, Najarro & E. Martínez, 2014 |
| Hydrangea breedlovei Samain, Najarro & E. Martínez, 2019 |
| Hydrangea carroniae Samain & E. Martínez, 2019 |
| Hydrangea macrophylla (Thunb.) Ser., 1830 |
| Hydrangea nahaensis Samain & E. Martínez, 2019 |
| Hydrangea nebulicola Nevling & Gómez Pompa, 1968 |
| Hydrangea oerstedii Briq., 1919 |
| Hydrangea opuloides (Lam.) K. Koch, 1869 |
| Hydrangea otontepecensis Samain & E. Martínez, 2019 |
| Hydrangea seemannii L. Riley, 1924 |
| Hydrangea sousae Samain, Najarro & E. Martínez, 2019 |
| Hydrangea steyermarkii Standl., 1940 |
| Hydrangea tapalapensis Samain, Najarro & E. Martínez, 2019 |
| Hydrangeaceae Dumort., 1829 |
| Hydrangeeae DC., 1830 |