Solanum dulcamara, also known as bittersweet, bittersweet nightshade, bitter nightshade, blue bindweed, climbing nightshade, fellenwort, felonwood, poisonberry, poisonflower, scarlet berry, snakeberry, trailing bittersweet, trailing nightshade, violet bloom, or woody nightshade, is a species of vine in the potato genus Solanum, family Solanaceae. It is native to Europe and Asia, and widely naturalised elsewhere, including North America, where it is an invasive problem weed. It occurs in a very wide range of habitats, from woodlands to scrubland, hedges and marshes.
Bittersweet is a semi-woody herbaceous perennial vine, which scrambles over other plants, capable of reaching a height of 4 m where suitable support is available, but more often 1-2 m high. The leaves are 4-12 cm long, roughly arrowhead-shaped, and often lobed at the base. The flowers are in loose clusters of 3-20, (1-1.5 cm) across, star-shaped, with five purple petals and yellow stamens and style pointing forward. The fruit is an ovoid red berry about 1 cm long, soft and juicy, poisonous to humans and livestock but edible for birds, which disperse the seeds widely. As with most Solanum species, the foliage is also poisonous to humans.
Bittersweet is used in naturopathy and herbalism. Its main usage is for conditions that have an impact on the skin, mucous membrane and the membrane (synovial membrane) around the joints. Bittersweet is considered by some to be a herbal remedy for treating herpes and allergies.
Although fatal human poisonings are rare, several cases have been documented. The poison is believed to be solanine.
Other common names for Solanum dulcamara include trailing nightshade, bittersweet, trailing bittersweet, climbing nightshade, blue bindweed, bitter nightshade, fellenwort, dogwood, woody nightshade, poisonflower, poisonberry, snakeberry, and scarlet berry.
The name bittersweet is also used in some areas for some species in the genus Celastrus (elsewhere referred to as the staff vines, family Celastraceae), e.g. american bittersweet (Celastrus scandens) and oriental bittersweet (Celastrus orbiculatus).