Bittersweet usually grows in damp inland habitats, but a prostrate variant also grows on shingle beaches. It has small purple flowers with yellow centres, and berries which turn from green to red. The berries are not poisonous unless eaten in huge quantities.
This plant also goes by the name of Woody Nightshade, and is sometimes mistakenly called Deadly Nightshade, but the true Deadly Nightshade (Atropa belladonna) has larger bell-shaped flowers and is highly poisonous.