Hydrangeaceae is a family of flowering plants in the order Cornales, with a wide distribution in Asia and North America, and locally in southeastern Europe. it comprises nine (or fewer) genera with 223 known species.
In its broad sense (as treated by the Angiosperm Phylogeny Group), the family includes 17 genera, but some botanists divide the family into two, with seven genera split off into a separate family, Philadelphaceae. The genera of Hydrangeaceae were formerly included in a much broader (but polyphyletic) Saxifragaceae.
The genera are characterised by leaves in opposite pairs (rarely whorled or alternate), and regular, bisexual flowers with 4 (rarely 5–12) petals. The fruit is a capsule or berry containing several seeds, the seeds with a fleshy endosperm.
- Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III" (PDF). Botanical Journal of the Linnean Society. 161 (2): 105–121. doi:10.1111/j.1095-8339.2009.00996.x. Retrieved 2019-07-11.
- "Family: Hydrangeaceae Dumort., nom. cons". Germplasm Resources Information Network. United States Department of Agriculture. 2003-01-17. Retrieved 2012-07-31.
- Christenhusz, M. J. M.; Byng, J. W. (2016). "The number of known plants species in the world and its annual increase". Phytotaxa. 261 (3): 201–217. doi:10.11646/phytotaxa.261.3.1.
- "GRIN Genera of Hydrangeaceae". Germplasm Resources Information Network. United States Department of Agriculture. Archived from the original on 2004-11-18. Retrieved 2012-07-31.