The common name “bittersweet” refers to two distinctly different vining plants, one of which poses a significant health hazard if ingested. The question of toxicity depends entirely on correctly identifying which species is present, as they belong to separate botanical families and produce visually different fruits and flowers. Understanding the specific characteristics of each plant is paramount, as one can lead to severe poisoning symptoms while the other typically causes only mild gastrointestinal upset.
Clarifying the Two “Bittersweet” Species
The first species, Woody Nightshade (Solanum dulcamara), is associated with serious toxicity and is a member of the nightshade family (Solanaceae). This plant is a semi-woody, scrambling vine that rarely grows to a large diameter. Its flowers appear as small, star-shaped clusters with five recurved purple petals and a prominent yellow cone of fused stamens. The berries mature from green to a shiny, bright red, appearing in loose clusters along the stem.
The second group includes the highly woody vines known as Oriental Bittersweet (Celastrus orbiculatus) and American Bittersweet (Celastrus scandens), which belong to the staff vine family (Celastraceae). These are vigorous climbers that develop thick, twisted, woody stems and are often used in seasonal decorations.
The fruit of the Celastrus species is a three-part, globe-shaped capsule. In the fall, this capsule splits open to reveal bright red-orange, fleshy, berry-like seeds. A key distinction is where the fruit appears on the vine; the native American Bittersweet produces fruit clusters only at the tips of the branches. Conversely, the invasive Oriental Bittersweet produces fruit clusters along the entire length of the stem. While the berries of Celastrus species can cause gastrointestinal upset, their toxicity is much lower than that of the Woody Nightshade.
Toxicity and Mechanism of Danger
The primary danger in Woody Nightshade (Solanum dulcamara) comes from its content of steroidal glycoalkaloids, including Solanine and Dulcamarine. These compounds are naturally produced by the plant as a defense mechanism against grazing animals. The mechanism of action involves the glycoalkaloids disrupting cell membranes and interfering with the nervous system’s ability to transmit signals. Specifically, these toxins inhibit the enzyme acetylcholinesterase, which leads to a disruption in nerve impulse transmission. This neurological effect is compounded by severe local irritation of the gastrointestinal tract.
The concentration of these toxic agents is not uniform across the plant’s life cycle. The highest levels of Solanine are found in the unripe, green berries, making them the most dangerous part of the plant. As the berries ripen and turn red, the concentration of glycoalkaloids decreases, but the entire plant—including the leaves and stems—still contains poison that can cause harm. Ingesting ten or more unripe berries is considered sufficient to cause poisoning symptoms in an adult. Children and small pets face a significantly greater risk due to their lower body mass.
Symptoms of Ingestion and Emergency Response
Ingestion of the toxic Woody Nightshade berries can lead to a range of immediate and delayed health effects involving both the digestive and nervous systems. Initial symptoms often manifest as severe gastrointestinal distress, including nausea, vomiting, abdominal cramping, and profuse diarrhea. This distress is caused by the toxins directly irritating the lining of the stomach and intestines.
As the toxins are absorbed into the bloodstream, they begin to exert their neurological effects. Affected individuals may experience dizziness, confusion, and unusual drowsiness. More severe neurological signs include dilated pupils, muscle weakness, and involuntary twitching. In cases of significant ingestion, particularly of unripe berries, the toxins can slow the heart rate and lower blood pressure, potentially leading to respiratory depression.
Symptoms may not appear immediately, so any suspected ingestion warrants immediate action. The potential for delayed symptoms necessitates professional medical evaluation regardless of the initial appearance of the individual. If a bittersweet berry is ingested, the immediate step is to call the national Poison Control Center at 1-800-222-1222, which is available in the United States and Canada.
This free, confidential service connects callers directly with toxicology experts who can provide specific, tailored guidance based on the amount and type of plant ingested. Do not attempt to induce vomiting unless specifically instructed to do so by a medical professional or the Poison Control Center, as this can sometimes cause further harm.
While waiting for assistance, several steps should be taken:
- Remove any remaining plant matter from the mouth.
- Note the time of ingestion and estimate the quantity of berries or plant parts consumed.
- If possible and safe, collect a sample of the plant, including any flowers or berries, to bring to medical staff for positive identification, which aids in determining the appropriate course of treatment.