Hydrangea?

Hydrangea?

Observation - Hydrangea? - UK and Ireland. Description: From summer of this year: I've seen this in a few gardens but I don't know what it actually is. I think it's a Hydrangea: it seems to grow with multiple thin, upright stems, peeling brown bark, fleshy toothed leaves held in opposite pairs: seems to eit

From summer of this year: I've seen this in a few gardens but I don't know what it actually is.

I think it's a Hydrangea: it seems to grow with multiple thin, upright stems, peeling brown bark, fleshy toothed leaves held in opposite pairs: seems to either layer or sucker itself into dense colonies.

Grows up to 5-6' in height.

All suggestions welcomed!