Hydrangeaceae Explained

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.^[1]

Description

The genera are characterised by leaves in opposite pairs (rarely whorled or alternate), and regular, bisexual flowers with four (rarely 5–12) petals. The fruit is a capsule or berry containing several seeds, the seeds with a fleshy endosperm.^[2]

Genera

The following genera are accepted:^[3]

• Carpenteria Torr.
• Deutzia Thunb.
• Fendlera Engelm. & A.Gray
• Fendlerella A.Heller
• Hydrangea Gronov. ex L.
• Jamesia Torr. & A.Gray
• Kirengeshoma Yatabe
• Philadelphus L.
• Whipplea Torr.

Phylogeny

The family Hydrangeaceae has two subfamilies, namely Jamesioideae and Hydrangeoideae. The subfamily Jamesioideae comprises the genera Jamesia and Fendlera.^[4] They are the sister group to the remaining Hydrangeaceae.^[5] The subfamily Hydrangeoideae has two tribes: Hydrangeae consists of Hydrangea s.l.,^[6] and Philadelpheae consists of Philadelphus, Carpenteria, Deutzia, Kirengeshoma, Whipplea, and Fendlerella.^[7] Carpenteria is the sister group to Philadelphus. Deutzia is the sister group to Kirengeshoma, and Fendlerella is the sister group to Whipplea.^[4] However the relationships among those three clades within the tribe Philadelphae are a bit unclear. The following cladogram summarizes results from different studies, and for each node it is noted which studies support the sister group positions of the following branches:

Notes and References

1. Christenhusz, M. J. M. . Byng, J. W. . 2016 . The number of known plants species in the world and its annual increase . Phytotaxa . 261 . 201–217 . 10.11646/phytotaxa.261.3.1 . 3 . free.
2. Web site: Hydrangeaceae - FNA . 2023-06-20 . floranorthamerica.org.
3. Web site: Hydrangeaceae Dumort. . . Plants of the World Online . Board of Trustees of the Royal Botanic Gardens, Kew . 30 June 2021 .
4. Kim, C., Deng, T., Wen, J., Nie, Z. L., & Sun, H. (2015). "Systematics, biogeography, and character evolution of Deutzia (Hydrangeaceae) inferred from nuclear and chloroplast DNA sequences." Molecular Phylogenetics and Evolution, 87, 91-104.
5. Kubitzki, K. (2013). "Flowering Plants. Dicotyledons: Celastrales, Oxalidales, Rosales, Cornales, Ericales." p. 206. Springer Berlin Heidelberg.
6. Samain, M. S., Wanke, S., & Goetghebeur, P. (2010). "Unraveling extensive paraphyly in the genus Hydrangea s.l. with implications for the systematics of tribe Hydrangeeae." Systematic Botany, 35(3), 593-600.
7. Hufford, L., Moody, M. L., & Soltis, D. E. (2001). "A phylogenetic analysis of Hydrangeaceae based on sequences of the plastid gene matK and their combination with rbcL and morphological data." International Journal of Plant Sciences, 162(4), 835-846.