Black nightshade is common in lowland cultivated habitats in NZ. It is typically less than 75cm tall, and often found in crops and gardens. It belongs to the same Solanum family as tomatoes, eggplands, capsciums and potatoes.
Many strains of Black Nightshade are easily controlled with herbicides except for Trifluralin. However there is resistance to to some sulphonylurea based herbicides, including chlorsulfuron and to metsulfuron-methyl. In these cases a second herbicide needs to be added.
Although it looks quite similar to deadly nightshade, the deadly version is seldom found in NZ and then typically only in Canterbury. According to the NZMA black nightshade is not highly toxic and small accidental ingestions of a few berries or leaves rarely leads to symptoms in humans.
There is also a native nightshade, however that is more commonly found in coastal scrub and forests.