Abstract
I'd welcome any help with the identification of this large grass which has defeated me!
© Luke Gaskell
The grass was found in a roadside woodland near Galashiels, in June 2020. It appeared to be very well established and may be a garden throw-out or birdseed alien. It is very large, perhaps 2m tall and completely hairless.

© Luke Gaskell
Here is a close up of the inflorescence. I think it is a Brome, but I've been unable to identify the species and I'd welcome any suggestions or ideas!