The Latin name Hydrangea
Let's begin at the beginning. For that we have to go back to 1739, when the botanist Grovonius gave this flower the Latin name Hydrangea. He thought that the shape was reminiscent of an ancient water pitcher. Combining the words 'hydro' (=water) and 'angeion' (=barrel or pitcher) resulted in the name Hydrangea. An appropriate name, since all hydrangea varieties need a lot of water.
The common name hortensia
Alongside the posh name Hydrangea, this lavish bloomer is commonly also referred to as hortensia. This name first occurred in 1771, and was invented by the French botanist Philibert Commerson. It's not certain what inspired him, but there is a suspicion that he named the flower after a woman. Perhaps it was the name of his mistress, or a well-known female astronomer with whom he was acquainted. It could also be that the name was suggested by upper class ladies. He had close links with Hortense de Nassau, the daughter of the Prince of Nassau, with whom he had previously returned from a botanical expedition.
Separate from any references to a particular lady, it is also argued that the name 'hortensia' derives from a loose translation of the Latin for 'from the garden'. The Latin word 'hortus' means 'garden', and Commerson found the hydrangea in the garden of the King of Mauritius, together with all sorts of other flowers and plants. Of course this could be true ...
As we said before, there's plenty to tell you about the names given to the hydrangea or hortensia. But what the truth is nobody knows, and so it remains guesswork ... That's not a problem, as long as you enjoy all the beauty that the hydrangea has to offer you!