Hydrangea angustipetala belongs to the H. scandens, H. chinensis species group (Hydrangea sect. Chinenses), whose species delimitation is still controversial.

This is a temporary placement by creating a taxa to place the observations with "angustipetala" type of plants into an distinct taxon ID, and merge the old synonym into a more widely accepted name.

Further study and taxonomic revision are needed to clarify the relationship among this group so as to decide whether to merge, split or retain these names.