Wild grapes are common in many natural areas. While many species are safe to consume, distinguishing them from potentially toxic lookalikes can be challenging. Accurate identification before foraging is paramount to ensure safety and prevent adverse health reactions. This requires careful observation of specific botanical features.
Identifying Wild Grapes
True wild grapes belong to the Vitis genus. These woody perennial vines often climb extensively, using branched tendrils opposite the leaves to grasp supports. Mature vines have reddish-brown bark that tends to shred or peel. Wild grape leaves are generally heart-shaped or broadly ovate, often displaying three to five lobes with distinct toothed margins. The veins on the underside of the leaves are typically raised.
The fruit grows in clusters, similar to cultivated varieties, but individual berries are usually smaller and more seedy. Ripe berries are typically dark purple to bluish-black, often covered with a powdery white “bloom.” Inside, true wild grapes contain two to four egg-shaped or pear-shaped seeds. Most true wild grape species are not poisonous, though some may cause mild digestive upset if consumed in large quantities due to tartaric acid and calcium oxalate crystals.
Common Toxic Lookalikes and Their Dangers
Several plants can be mistaken for wild grapes, and some of these lookalikes are toxic. Understanding their distinguishing features is crucial for safe foraging.
Canada Moonseed (Menispermum canadense)
This vine has leaves resembling wild grapes but lacks tendrils. Its fruit is the most reliable differentiator: moonseed berries contain a single, crescent-shaped seed, unlike the multiple, rounder seeds in true grapes. All parts of Canada moonseed, especially the fruits and seeds, contain toxic alkaloids like dauricine, which can be fatal if ingested.
Virginia Creeper (Parthenocissus quinquefolia)
Often confused with wild grapes, Virginia Creeper also has tendrils, but these often have adhesive disks at their tips. A key difference is its palmately compound leaves, consisting of five leaflets radiating from a central point, not the single, lobed leaves of wild grapes. Its bluish-black berries grow on reddish stems in looser clusters than grapes. These berries and leaves contain calcium oxalate crystals, which can irritate the mouth, tongue, and throat upon ingestion.
Porcelain Berry (Ampelopsis glandulosa or brevipedunculata)
This invasive vine also belongs to the grape family, leading to frequent misidentification. Its berries are distinctive, displaying a range of colors including blue, pink, white, green, and turquoise, often on the same vine. This differs from the uniformly dark color of ripe wild grapes. Porcelain berry flowers and fruits typically point upwards, while native grapes tend to droop. The pith of a porcelain berry stem is solid white, unlike the brown pith of native grape stems.
Symptoms of Ingestion and When to Seek Help
Ingesting toxic lookalikes can lead to a range of symptoms, from mild irritation to severe systemic effects. Initial reactions often involve gastrointestinal distress. For example, Virginia Creeper berries can cause immediate irritation, redness, and swelling in the mouth, lips, and throat due to calcium oxalate crystals, followed by nausea, vomiting, and diarrhea.
Canada Moonseed ingestion, being highly toxic, can result in severe symptoms. These include abdominal pain, vomiting, diarrhea, and neurological effects such as convulsions, dizziness, weakness, or seizures. Cardiac issues, including irregular and rapid heartbeats, may also occur and can be fatal, especially in children. Porcelain Berry typically causes milder gastrointestinal upset.
If ingestion of a potentially toxic plant is suspected, contact Poison Control immediately at 1-800-222-1222, even if symptoms have not yet appeared. Providing information about the ingested plant, if possible, assists medical professionals. Seek immediate medical attention by calling emergency services if the individual collapses, has difficulty breathing, experiences seizures, or loses consciousness.