Silverleaf Nightshade, scientifically known as Solanum elaeagnifolium, belongs to the toxic nightshade family (Solanaceae). The plant contains toxic compounds that pose a risk to both humans and livestock. Every part of the Silverleaf Nightshade is considered toxic, though the concentration of dangerous substances varies throughout the plant’s structure.
Identifying Silverleaf Nightshade
Silverleaf Nightshade is recognizable by its physical characteristics. The stems and leaves are covered with a dense layer of fine, silvery hairs, creating a velvety, grayish appearance. This perennial herb typically grows to about three feet tall and often features small, sharp prickles along its stems and sometimes on the main veins of the leaves.
The flowers feature five petals arranged in a star shape, generally bright purple or blue, though they can occasionally be white. They have a prominent yellow center and appear in clusters. Following the flowers, the plant produces round berries, which are initially green and striped, but mature to a yellow or orange-yellow color.
The Toxic Compounds and Dangerous Parts
The toxicity of Silverleaf Nightshade is due to steroidal glycoalkaloids, primarily solanine. These naturally occurring chemicals serve as a defense mechanism against pests and grazing animals. Once ingested, the glycoalkaloids irritate the gastrointestinal tract directly.
More dangerously, these compounds break down in the body to release alkaloids or alkamines, which act as neurotoxins. This neurotoxic action involves inhibiting the enzyme acetylcholinesterase, disrupting the normal function of the nervous system.
While all parts are toxic, the highest concentration of these harmful compounds is found in the berries, particularly when they are green and unripe. The leaves and stems also contain toxins, and toxicity is not lost if the foliage is dried, meaning contaminated hay remains a risk to livestock. Ingestion of ripe berries is hazardous because they can resemble small, tempting tomatoes to children or pets.
Signs of Poisoning and Immediate Action
Symptoms of poisoning in humans often begin with severe gastrointestinal distress, including nausea, vomiting, abdominal pain, and diarrhea. As the toxins affect the nervous system, other signs may include headaches, dizziness, confusion, and a rapid or irregular heartbeat.
Animals, especially cattle and horses, are highly susceptible to the plant’s toxins. Livestock symptoms frequently include excessive salivation, labored breathing, weakness, and lack of coordination. In severe cases, high-volume consumption of the berries can lead to muscle tremors, depression, paralysis of the rear legs, and collapse.
Immediate action is necessary if ingestion of any part of the Silverleaf Nightshade is suspected. For human exposure, contact the United States National Poison Control Center immediately at 1-800-222-1222. If a pet or livestock animal is suspected of consuming the plant, contact an emergency veterinarian or animal poison control center.