Black Nightshade (Solanum  nigrum)

Solanum nigrum is an annual herb that is moderately poisonous (although possibly deadly).  All plant parts are potentially toxic, And the berries are often higher in toxicity than the leaves and stem. The plant is common throughout the United States east of the Mississippi River, and Southern Canada. (Reed).  It can be found along agricultural field and garden boarders. Although it may reach heights greater than 30 inches, in southwestern Wisconsin, I have rarely seen the plant reach heights greater than 12 inches tall.  I most often find Solanum nigrum growing along agricultural field boarders.  The plant seems to favor the tilled, somewhat well drained soils.

©Daniel Reed-www.2bnthewild.com

Solanum nigrum seedlings can be identified by alternating leaves with maroon colored markings on the underside, and short hairs on the hypocotyl.  The adult plant leaf margins are generally slightly lobed, and the stems take on the maroon color found in the young seedling leaves.

Solanum nigrum produces white, star-shaped flowers arranged in clusters.  Blooms first occur in early summer and continue into mid fall. These flowers can reach up to 0.3 inches wide.  They have 5 regular parts, reflexed petals, and a protruding yellow beak that is formed by the stamen and pistil (Peterson p.72).

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Table 1: Classification of Solanum nigrum (The PLANTS Database)    

Plants develop their own poisons to fight off disease. The natural pesticides found in potatoes, solanine and chaconine, are potent carcinogens and the same toxins that are found in Solanum nigrum (Munro 5-6).

According to the University of Maryland Medicine, solanine affects the central nervous system and gastrointestinal system. Symptoms usually occur during digestion. After ingesting the toxic berries you may develop a fever, followed by violent stomach cramps, vomiting and diarrhea. The effects of solanine on the nervous system include: headache, delirium, loss of sensation and hallucinations (Kennedy 2).

Fortunately, cases in which people or animal eats Solanum are rare. The plant and berries are small in size which makes them difficult to spot, and not worth gathering.  The most common danger with Solanum is accidentally incorporating the plant into feed (hay, silage, pellets). When crops are harvested, it is possible to cut the Solanum plant as well. Although some toxicity is lost during drying, the plant remains toxic.  When the feed is injested the toxins effect is the same on animals as humans.  However, cases of animal death from injesting Solanum nigrum are rare.  Treatment is purely symptomatic until the effect wears off in two to three days (Goetz 10-11).

Solanum nigrum has been found in Europe, South America, China and North America. There are also many other species of Solanum throughout the world that contain the same toxin.  Although the following list is not all-inclusive, they are the more common varieties.  These species include buffalobur (Solanum cornutum), Jerusalem cherry (Solanum pseudocapsicum), Hairy Nightshade (Solanum physalifolium), the common white potato (Solanum tuberosum), Carolina Horsenettle (Solanum carolinense), and Climbing Bittersweet (Solanum dulcamara)(Lee, 4).

This page was last updated on December 7, 2003.

If you have any corrections or comments, please feel free to e-mail me at danielleyahn@hotmail.com