Poisonous Potato Solanum carolinense

Carolina horse nettle is a native warm-season perennial herb or subshrub that grows erect or sprawling and is spread by rhizomes and seeds. It can grow up to 4 feet tall and has prickles along the stems and leaves. The light violet or white star-shaped flowers appear in the summer and fall. Its fruits are green berries that look like very small tomatoes. As the fruit ripens, it turns yellow and appears wrinkled. The plant is a member of the Solanaceae or nightshade family which also includes tomatoes, potatoes, eggplants, and peppers. 

This plant is native to parts of the United States, Canada, and Mexico. It is found in the central and southern United States usually in pastures, cultivated fields, disturbed sites, and along roadsides.  It is considered a noxious weed in several states.  

The genus name, Solanum, is from the Latin word, solamen, which means "comforting or soothing." The species name, carolinense, is Latin for "Carolina" where it was identified.

The Carolina horse nettle prefers full sun and is tolerant to wet and dry conditions. They can grow in sandy or loamy soils. They can easily become weedy and aggressive in disturbed sites. This plant is not recommended for most gardens.

The plant has very deep taproots and spreading rhizomes. The stems are prickly and open-branched. The leaves are dull green with wavy or coarsely lobed margins and are covered with star-shaped hairs. The flowers grow in clusters or cymes and may have 5 to 20 light violet or white star-shaped blooms. The fruit is a smooth green berry that will turn yellow and wrinkly when it matures. It ripens in the fall and may last through the winter months.

The plant is pollinated by bumblebees and insects. Quail and wild turkeys eat the fruits.

All parts of the Carolina horse nettle are poisonous to livestock and humans if ingested. Livestock may avoid eating the plant due to the prickles on the stems and leaves. The plant contains a toxin known as solanine and has the highest level in the fall. The berries are the most toxic when they are mature, but the leaves seem less toxic. 

Seasons of interest:

Bloom:  Summer and Fall        Fruits:   Fall and Winter

Quick ID Hints:

• erect or sprawling perennial
• prickly stems
• leaves alternate, ovate, coarse lobed margins or wavy, star-shaped hairs
• flower clusters of light violet to white star-shaped blooms with protruding yellow stamens in the center
• smooth, glossy, green berry fruit that looks like a small green tomato and turns yellow when ripens

Insects, Diseases, and Other Plant Problems:  The Colorado potato beetle, eggplant flea beetle, and tobacco hornworms feed on this plant. The Carolina horse nettle is a weed in gardens or field crops that have reduced tillage. The colonies of Carolina horse nettle are difficult to control and eliminate. They are resistant to some herbicides. Protective clothing and gloves should be worn when handling this plant because of the spines on the stems and leaves.