Solanum carolinense, commonly called Horse Nettle, is a widespread, perennial weed native to North America and a member of the Solanaceae family. The plant is characterized by its aggressive growth and is frequently found in pastures, cultivated fields, and disturbed areas across the United States. It is unequivocally poisonous to humans and most livestock if ingested. This toxicity is consistent throughout the plant’s life cycle, meaning all parts of the weed should be handled with caution.
How to Identify Horse Nettle
Identifying Horse Nettle involves looking for several distinguishing physical features, the most noticeable being its sharp, stiff, yellowish prickles. These spines are found on the upright stems (one to three feet tall), leaf stalks, and the main veins on the underside of the leaves. The leaves are alternate, oblong to egg-shaped, and often feature irregular, wavy lobes.
The plant produces small clusters of star-shaped flowers, usually white or pale violet, recognized by the five bright yellow anthers clustered in the center. Following the flowers, the plant develops small, round berries that resemble tiny tomatoes. These berries start green and mature into a smooth, opaque yellow, often persisting through the winter.
The Toxic Agents in Horse Nettle
The toxic properties of Horse Nettle are attributed to glycoalkaloids, a class of compounds that includes the potent chemical Solanine. Solanine is present in all parts of the plant, irritating the mucous membranes of the mouth and gastrointestinal tract upon ingestion, and also affects the autonomic nervous system.
The concentration of Solanine varies significantly by plant part and maturity. The highest levels are found in the unripe, green berries, making them the most dangerous part to consume. The concentration decreases in the ripe yellow berries, followed by the leaves, stems, and roots.
What Happens After Ingestion
The physiological reaction to ingesting Horse Nettle, or Solanine poisoning, can range from mild discomfort to severe, life-threatening symptoms. Initial symptoms typically involve the gastrointestinal system, often appearing within eight to ten hours after consumption. Milder signs include abdominal pain, nausea, vomiting, and diarrhea.
If a larger amount is consumed, effects can progress to involve the central nervous system. Severe symptoms may include headaches, fever, confusion, agitation, hallucinations, slowed pulse, difficulty breathing, paralysis, or coma.
Immediate Steps and Prevention
If Horse Nettle is ingested, seek expert medical advice immediately, even if no symptoms are present. Contact the national Poison Control Center (1-800-222-1222) 24/7, providing the person’s age, weight, the plant part consumed, estimated amount, and time of ingestion.
Prevention focuses on identification and removal, particularly in areas accessible to children and pets. Educate children to never eat wild berries or plants without confirmation that they are safe. When handling the plant, wearing gloves is recommended to protect the skin from the sharp prickles, and destroying the plant before it produces berries prevents future spread.