Bittersweet nightshade is native to Europe and Asia. It was introduced to North America for ornamental and medicinal purposes and became widespread by the late 1800s. It is now considered an invasive weed in most US states and Canadian provinces.
Bittersweet nightshade is a perennial, climbing vine. It grows in a wide range of habitats but prefers not to be in full sun. It can be found growing along hedgerows, forest edges, riparian zones and in forest understories. Its stems and berries have been used in herbalism to treat skin conditions such as herpes and eczema. However, the berries are toxic when eaten by humans.
Bittersweet nightshade may be confused with Oriental bittersweet (Celastrus orbiculatus), which is also an invasive species and grows in PEI. Here are some distinguishing features of bittersweet nightshade that may help you positively identify it:
Stem is woody and can grow to 10 ft
Leaves are heart-shaped and arranged alternately
When leaves are crushed they emit an unpleasant smell
Clusters of flowers extend from the stem
Flowers are blue-violet, star-shaped, with protruding yellow anthers
Flowers bloom May to September
Forms clusters of green, ovaloid berries that are are red when ripe
Spread by birds who eat the berries and by pieces of stem and root that are moved by soil or water