Black nightshade
General poisoning notes:
Black nightshade (Solanum nigrum) is a naturalized herb found scattered across southern Canada in waste places. This plant can be easily confused with eastern black nightshade, a native herb, which is more commonly found in its range in eastern Canada (see taxonomy and distributions in Ogg et al. 1981, Bassett and Munro 1985). Black nightshade contains toxic glycoalkaloids in the plant. The highest concentration is in the green immature berries. All kinds of animals can be poisoned after ingesting nightshade including cattle, sheep, poultry, and swine. Children have been poisoned and have died after ingesting unripe berries. The ripe berries cause reduced symptoms of mild abdominal pains, vomiting, and diarrhea (Cooper and Johnson 1984, Lampe and McCann 1985). Some Canadian garden catalogs sell seed for garden huckleberry (Solanum melanocerasum All.; also previously known as Solanum nigrum L. var. guineenseL.). This plant has edible black fruits that can be cooked for use in pies, jams, and preserves. The plant may persist from seed for more than a year in gardens in warmer parts of Canada. There is no evidence that the ripe fruits are toxic. Other species of nightshade occur in Canada, and some may contain small amounts of toxins. Eastern black nightshade (Solanum ptycanthumDun ex DC.) may contain small amounts of toxin in the green berries. Berries of hairy nightshade (Solanum sarrachoides Sendt.) have been tested as a teratogen in hamsters but the results were not statistically significant (Keeler et al .1990).
Nomenclature:
Scientific Name: Solanum nigrum L.
Vernacular name(s): black nightshade
Scientific family name: Solanaceae
Vernacular family name: nightshade
Solanum nigrum L.
Geographic Information
Alberta, British Columbia, Manitoba, New Brunswick, Nova Scotia, Ontario, Quebec, Saskatchewan
Notes on Poisonous plant parts:
All parts of the plant contain alkaloids, especially the green immature berries. The concentration increases in the leaves until plant maturity. The ripe black berries contain little alkaloidal content and can sometimes be eaten with no harmful effects(Cooper and Johnson 1984).
Toxic parts:
All parts, immature fruit, leaves
Notes on Toxic plant chemicals:
Toxic glycoalkaloids, including solanine, solasodine, and chaconine are found in black nightshade, especially in the green immature berries. Nitrates can also accumulate in the plant material (Cooper and Johnson 1984).
Toxic plant chemicals:
chaconine
nitrate
solanine
solanine
solasodine
Chemical diagram(s) are courtesy of Ruth McDiarmid, Biochemistry Technician, Kamloops Range Station, Agriculture and Agri-Food Canada, Kamploops, British Columbia, Canada.
Animals/Human Poisoning:
Note: When an animal is listed without additional information, the literature (as of 1993) contained no detailed explanation.
Cattle
General symptoms of poisoning:
Breathing, labored, constipation, death, diarrhea, incoordination, muzzle, dry
pupil dilation, temperature, depressed.
Notes on poisoning:
Symptoms of poisoning are similar to those for swine. Cattle can also develop edema from the lower jaw to the front of the legs (Cooper and Johnson 1984).
Humans
General symptoms of poisoning:
Abdominal pains, death, diarrhea, dizziness, temperature, elevated, unconsciousness, vomitingNotes on poisoning:
Humans have been poisoned and have died (rarely) after ingesting usually green immature berries. Ripe, black berries have little toxin in them, although abdominal pains and vomiting could occur. Symptoms usually occur only after a latent period of several hours and may persist for several days. Symptoms resemble those of bacterial gastroenteritis and include headache, speech impairment, and unconsciousness (Cooper and Johnson 1984, Lampe and McCann 1985).
Poultry
General symptoms of poisoning:
Death
Notes on poisoning:
In one case in Maryland, over 300 pullets died when they were allowed to feed on a field overgrown with black nightshade (Reynard and Norton 1942).
Swine
General symptoms of poisoning:
Breathing, rapid, death, incoordination, muscle spasms, temperature, depressed.
Notes on poisoning:
Pigs have been poisoned after ingesting black nightshade. Symptoms included rapid pulse and respiration, pale mucous membranes, dilated pupils, depressed temperature, incoordination, and tremors (Cooper and Johnson 1984).
