Bromus interruptus

About

Bromus interruptus, commonly known as the interrupted brome, is a flowering plant in the grass family. It was endemic to southern and central England, but it went extinct in the wild in 1972. After several decades in cultivation, the interrupted brome was re-introduced to Aston Rowant National Nature Reserve in 2004, marking the first known re-introduction of an extinct plant in Britain. The plant was a weed of waste places and arable agriculture, particularly of sainfoin cultivation. It can be distinguished from all other Bromus species by its deeply split, or bifid, palea.

Summary from Wikipedia