Carolina horse nettle

Solanum carolinense L.

Solanaceae (Nightshade family)


Description

Carolina horse nettle is a coarse, branching, warm-season perennial in the Nightshade family. It grows 1 to 3 feet high.

Carolina horse nettle has large spines on the stems and leaves. Each of its mostly oval leaves has several large teeth or shallow lobes on both sides. On the underside are microscopic, star-shaped hairs.

The clustered flowers are pale violet to white and give rise to spherical fruit. The fruit is about › inch in diameter; it is green with light green vertical bands until maturity, when it becomes uniformly yellow.

Because of its many spines, the forage value of Carolina horse nettle is poor for wildlife and livestock. The fruit is poisonous to livestock.


Habitat

This plant grows across the eastern part of Texas and the entire eastern half of the United States. It is found mostly in sandy soils in fields, open woodlands and waste places.


Toxic Agent

Horse nettle is a nightshade. Nightshades contain glycoalkaloids, which are broken down in the body to sugars and alkaloids. The toxicity may depend upon the maturity of the plants, because more toxins are present in the fruits than in the leaves.

Almost every animal species has been poisoned by nightshade, but S. carolinense is probably mostly responsible for cases involving cattle and horses. Hay and silage containing the mature plants have been associated with poisoning and deaths.


Signs of Livestock Ingestion

It is thought the glycoalkaloids are responsible for the clinical signs associated with the gastrointestinal tract, and the alkaloids are associated with the signs in the central nervous system. The signs may include: Anorexia; Depression; Excess salivation; Diarrhea or constipation; Trembling; Weakness; Colic.

The star-shaped hair and seeds of this plant are readily identifiable in the gastrointestinal contents of acutely poisoned animals by microscopic techniques.


Management Strategies

Carolina horse nettle is not a palatable plant, and consumption by animals should not be forced. Avoid including the mature plants in hay, silage or green chop.

Chemical control strategies may be warranted in fields or pastures infested with dense populations. Apply 0.6 to 0.9 pound a.i./acre of Grazon P+D® as a broadcast treatment or a 1 percent solution as an individual plant treatment when plants begin to flower in the spring.


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