Solanum dulcamara
A member of the Nightshade family (Solanaceae), it is sometimes called Deadly Nightshade because its leaves and unripe fruit contain the alkaloid solanine. Although the toxin is not fatal, it can cause problems for young children if eaten in any quantity.
It is also a close relative of the common garden tomato (look at its leaves below), but was dubbed "bittersweet" because of the tasete of its leaves.
