Carolina Horsenettle: A Poisonous Yellow Tomato Lookalike

A member of the nightshade and tomato family (Solanaceae), Carolina Horsenettle (Solanum carolinense) is a plant that can pose a threat to foragers and inquisitive children.

It holds a number of colloquial names, including Devil’s Tomato and Poisonous Potato, which begin to hint at the toxicity of the plant. When ripe, the fruit of the Carolina Horsenettle greatly resembles yellow tomatoes — which can look tempting to children and inexperienced foragers alike. However, unlike our usual garden varieties, the fruit of the Carolina Horsenettle is very poisonous, and will cause serious issues if eaten…

What Are The Active Compounds in Carolina Horsenettle?

Like deadly nightshade, the toxic alkaloid solanine is present in Carolina horsenettle. It’s an incredibly toxic compound and is the toxin responsible for making green (sun-exposed) potatoes so poisonous. Solanine is present in all plant parts, and it cannot be destroyed by boiling or cooking. The leaves and fruits contain the highest quantities of solanine.

Carolina horsenettle contains solanine as a natural defense mechanism. It helps to protect the plant from predators and also livestock, which will also usually avoid eating the plant.

Carolina Horsenettle Poisoning Symptoms

Symptoms will vary depending on how much is accidentally consumed. In an adult, one or two fruits will cause severe nausea, fever, diarrhea, dizziness, stomach cramps, and an irritated throat. But if a larger amount is consumed, the circulatory system and lungs can also be affected, and death may follow if treatment isn’t received quickly. Solanine can slow the heart rate, and also breathing, which can cause serious complications. Even relatively small doses of solanine can be fatal in young children, so parents must be vigilant when out exploring with little ones.

What is the Medicinal Potential of Carolina Horsenettle?

Usually branded only as a toxic lookalike, the Carolina horsenettle was once valued as a medicinal plant. Many Native American groups used Carolina horsenettle in medicinal recipes for its sedative and antispasmodic effects. The leaves were brewed into a tea to soothe sore throats and also used topically to treat poison ivy rashes. The plant would also be used to help with the removal of worms, and even used to treat epilepsy and convulsions. European colonizers also began to use the plant, until other medicinal herbs became preferred.

Cultural Symbolism of Carolina Horsenettle

The name ‘Carolina’ comes from the State in which the plant was first formally identified. However, the ‘Horsenettle’ likely refers to the toxic effect that plants can have on livestock and horses in particular.

Although ‘nettle’ features in the name, the Carolina horsenettle is not a true nettle, and it is not part of the nettle family Urtica.

Today, Carolina horsenettle is most widely viewed as a weed. It spreads via seeds that form in the rounded fruits, but it can also spread through rhizomes too, making it particularly invasive. Farmers tend to use specially formulated herbicides to remove Carolina horsenettle from pastures and crop fields.

What Does Carolina Horsenettle Look Like?

Carolina horsenettle has the telltale lobed leaves which can be found on other members of the nightshade family. They’re coated in fine hairs, and the stem is also spined.

In summer, the plant will have delicate, star-shaped white flowers with a yellow center. The fruit is dark green when it first forms and soon ripens to a deep golden yellow when mature. The fruits will appear on trusses, much like our usual garden tomatoes, and the fruit hugely resembles yellow tomatoes. Its similarity to tomatoes makes it dangerous to novice and inexperienced foragers.

Where Does Carolina Horsenettle Grow?

Carolina horsenettle is native to the southeastern states of North America, but it has since spread across the continent. Plant sightings are also often recorded in Europe, Asia, and even Australia.

It’s a perennial plant that can establish quickly in disturbed soil and form strong roots. You might come across it growing along roadsides, and also at the edges of meadows and fields.

Conclusion

Although it is now considered an invasive weed in many states, Carolina horsenettle still has a humble beauty with its delicate star-shaped flowers and bright yellow fruits. While it cannot be eaten by humans or livestock, it still has a valuable place within its native ecosystem. Birds and other wildlife rely on the fruits, and a number of insects including moths and bees feed on the pollen.