Common glasswort (Salicorna europaea), or marsh samphire, in its red autumnal colour. This edible plant grows in salt-marshes and in this abandoned salt pan. Before the 19th century, due to it's high sodium content, glasswort was used in the glass making process. The stems were dried and burnt to salty ashes and the ash was then heated with sand until the silica in the mix fused into a crude glass. If the ash is leached with limewater a solution of caustic soda is produced that can be mixed with animal fat to produce a soap. Photographed in Guerande, Brittany, France.