Solanum dulcamara | bittersweet nightshade
Commonly called Deadly Nightshade, but that is more usefully reserved for Atropa belladonna, which has been used as a poison since ancient times. Fatalities from this are rare and are usually little kids eating the bright red berries.
Flickr page for this photo.
Visit the Eye for Science Flickr group.
Get the "Eye for Science" widget
here
and install it on your own blog. Spread the scienticity!