Gunnera got loose

This gunnera has been flourishing in a gully by the road between Glendaruel and Colintraive for all of the nearly 30 years we have lived here , but today I looked at it properly for the first time , noticing the very prominent flowering spikes

I presume it must have been a garden escapee , and between it and Loch Riddon there is a large house and garden though both rather decayed now.