False Barley

From Wikipedia: Hordeum murinum, commonly known as wall barley or false barley, is a species of grass.
They can grow to 30 cm in height and its unbranched spikes can reach 10 cm long. It is quite widespread and common. It grows during May - July in mainly costal areas. It produces small, dry nutlets and its leaves can be 8 cm wide with short blunt Ligules.
It is absent throughout most of Ireland and Scotland but is common in England and Wales.