Close-up View of the Hydrangea
- Photographic study by Brian Johnston of Hydrangea macrophylla 'Blaumeise', with many fine images both macroscopic and microscopic.
- http://www.microscopy-uk.org.uk/mag/artjun07/bj-hydrangea.html

Hydrangea
- Classification and range maps for all species in the United States.
- http://plants.usda.gov/java/profile?symbol=HYDRA

Hydrangea sp.
- image
- http://www.botany.hawaii.edu/faculty/carr/images/hyd_sp.jpg