We received a Facebook message the other day with a question about a plant with a tiny green berry that smelled like a tomato and looked like a tomato when it was cut open.
But don't eat it. It's not a tomato.
Black nightshade (Solanum ptycanthum) is in the nightshade family, which also includes tomatoes and potatoes, and is a common plant in Iowa woodlands.
It produces white, star-shaped flowers, sometimes tinged with purple, and small, round berries that are considered toxic when green. They are a dark purple when ripe and are about the size of a pea or blueberry.
Both the green berries and foliage of the plant may contain the toxic alkaloid solanum --- hence the genus name. If the green berries or foliage are ingested, it can cause a variety of symptoms.
A variety of animals eat the mature fruit of the plant, and many foragers think it would be fine for humans to eat the dark berries as well, although it can be a controversial topic. Animals that eat the fruit, according to Illinois Wildflowers, include the ruffed grouse, wild turkey, eastern meadowlark, gray catbird and swamp sparrow as well as raccoon, striped skunk, white-tailed deer and rodents. The seeds survive the digestive tract and are deposited in places other than woodlands, often ending up in gardens and landscaping.
Mammalian herbivores tend to avoid the leaves.
The controversy about nightshade's toxicity seems to come about because it has been used animal fodder in smaller quantities, and the production of the alkaloid solanum may vary with climate, season and soil type, according to an article I read from Root Simple or from Foragers Harvest.opens PDF file
Plus, black nightshade is often confused with toxic deadly nightshade (Atropa belladonna) that causes delirium and hallucinations.
However, according the University of Iowa Stead Family Children's Hospital website, black nightshade can still cause dry mouth, enlarged pupils, diarrhea, stomach pain, vomiting, change in pulse rate, shock, delirium, fever, hallucinations, headache, loss of sensation, paralysis or sweating. Death is unlikely. Call poison control at 1-800-222-1222 if ingested.
Nightshade can be a confusing plant, because the common names of the many different species are often lumped under "nightshade" or "black nightshade." It is found around the world, from Solanum nigrum, S. americanum, S. ptychanthum, S. douglasii and other closely allied species.
The positive is, nightshade is a relatively easy plant to pull from your garden or landscaping, no matter the species.