Euphorbia peplis

Euphorbia peplis, the purple spurge, is a species of "Euphorbia", native to southern and western Europe, northern Africa, and southwestern Asia, where it typically grows on coastal sand and shingle.
It is a small, prostrate annual plant, the stems growing to long, typically with four stems from the base. The leaves are opposite, oval, long, grey-green with reddish-purple veins.
At the northern edge of its range in England, it has always been rare, and is now extinct.