The common nightshade, equally well known as the black nightshade, is also sometimes referred to as stubble-berry, deadly, and garden nightshade.
The common nightshade is a low, nearly smooth, much branched, and often spreading, annual plant from one to two feet high. The stems are somewhat rough-angled. The leaves are oval, tapering, two to four inches long, with few-toothed or wavy margins. The flowers are small, white, star-shaped, in drooping clusters of two to five. The berries are round, black when ripe. The plant blooms from July to September, and in the middle of the summer it is quite a common thing to find all stages of ripening fruit from pale green to black, as well as freshly opened flowers, all on the same plant.
Photo - F. Fyles.
It is widely distributed throughout the world except in extreme north and south. In Canada it is found on shaded as well as open ground from coast to coast.
There seems to be no doubt that this plant must be regarded as poisonous, but under certain conditions of soil and climate the toxicity evidently varies. Thus we read that, the "berries have been used instead of raisins for plum puddings, with no effects out of the ordinary" (Ewart), and again "Children have been poisoned by the berries, but may on occasion eat them with no other ill effect than a stomach ache, or, if eaten in excess, sickness and purging" (H. C. Long). Chesnut says: "The amount of poison present in any part of this plant varies with the conditions of growth. The more musky-odoured plants are the most poisonous. In some, the amount of alkaloid in the ripe fruit and leaves is so small that these parts may be, and are, consumed in considerable quantity without any ill consequences. Poisoning does sometimes follow, but it is not clear whether this is due to improper preparation or to careless selection of the parts used. The use of black nightshade for food is certainly not to be recommended."
The common nightshade contains the alkaloid solanine, which is found in larger quantities in the partially ripened berries. It also contains solanidine which, though poisonous, is not violently so. H. C. Long says "a small quantity of solanine is present in the stem and berries, but these are probably less poisonous than green potatoes."
Cases of poisoning (see Chesnut) have been recorded for calves, sheep, goats and pigs, and according to Lehmann, Schraber, and Haller, the berries are poisonous to ducks and chickens.
The characteristic symptoms, as given by Chesnut, are about the same in man and animals, i. e., stupefaction, staggering, loss of speech, feeling, and consciousness; cramps, and sometimes convulsions. The pupil of the eye is generally dilated.
Remedy and Means of Control: As both the common nightshade and the three-flowered nightshade are annual plants, they may be readily exterminated by pulling or close cutting when in flower. If, however, the fruits have already formed the cut tops should be buried in the compost heap, where fermentation will destroy the vitality of the seed; or they may be burned.