Mystery Plant! #751

John Nelson

Posted 11/29/23

By John Nelson

(Photo by Linda Lee.)

It’s a member of the tomato family, and it doesn’t matter which way you pronounce it. The tomato family is also quite properly referred to as the potato family, as well, and again, don’t worry about pronunciation. The take-home here is that the family’s botanical name is Solanaceae, and it is a big family at that, including nearly 4,000 species around the world. The Solanaceae contains some extremely important food plants, the most well-known surely being Irish potato…not to be confused with the “sweet” potato which is quite different (and a member of the morning-glory family). Tomatoes, too, along with their cousins, the various peppers, are also important economic crops. Finally, many cultivated species are members of this family, bringing us popular garden plants…such as the old stand-by, petunia.

Be aware though, that a number of members of this family are quite poisonous when consumed: Jimson weed and cultivated daturas are very dangerous. A wide variety of chemical constituents, many of which are technically alkaloids, result in this toxicity. Besides their general toxicity, some of these compounds have important physiological effects on humans. For example, the European herb known as “bella donna” produces berries containing a juice, which when dripped into the eyes, causes marked dilation of the pupils. Wide-open pupils are attractive, and thus ladies of the Italian Renaissance would use this as a beauty technique. That’s where the name “bella donna” comes from…

(Photo by Linda Lee.)

Our Mystery Plant is actually a relative of the European bella donna, but is native to America. It is common now just about all over the lower 48 states, although it is probably native only to the eastern half of the country. It is a perennial herb, producing a tough, prickly stem, and irregularly-lobed leaves. The plants like to show up in waste places, including roadsides and vacant lots. (And in your garden, if you give it a chance.) It blooms in the summer, producing attractive, star-shaped flowers, each with five white or lilac petals. Five stamens are in each flower, and interestingly, the pollen-containing anther of each stamen is fused to its neighbor along its sides, forming a sort of bright yellow tunnel through which the style emerges. These anthers are a bit unusual in that instead of splitting open to release pollen, a small pore develops at the tip through which the pollen exits. Pollination results in marble-sized green, striped berries, which are strikingly similar in appearance to a cherry tomato. By late fall, the berries will have turned yellow, and they hang on, commonly, well until after the first frosts. If you tear into one of these cherry tomato look-alikes, you’ll find plenty of little yellow seeds. Although the blossoms and berries are pretty, you won’t hear too many kind things said about this little plant. It’s basically a pest.

(By the way, there is a related species, commonly grown as a potted plant, which you might be seeing at the mall these days, or for sale at your local supermarket. This one has bright red or orange fruits, and is sometimes called “Christmas cherry”…)

[Answer: “Horse nettle,” Solanum carolinense]

John Nelson is the retired curator of the Herbarium at the University of South Carolina, in the Department of Biological Sciences. As a public service, the Herbarium offers free plant identifications. For more information, visit or email

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