These Are the Most Dangerous Flowering Weeds That May Be in Your Yard

This plant produces a white bloom that looks a bit like a morning glory, but from root to leaves, this plant is a no-no. Also called devil's snare, the plant's seeds, roots, stems, and leaves are all dangerous if ingested. Not only does it cause heart palpitations, respiratory and circulatory issues, but the seeds can cause terrifying hallucinations and even death.

It's just common sense to beware of any flower that has "death" in its name Zygadenus venenosus is no exception. The plant has delicate blooms that hint at its relation to the lily family. Don't let the fact that it's a part of the lily family fool you, because all parts of this plant are toxic, including the bulb, which looks like a wild onion. This pretty plant can cause vomiting, convulsions, and death.

Atropa belladonna is commonly known as deadly nightshade and it has the distinction of being one of the most toxic plants in the entire hemisphere. The dark purple, bell-shaped flowers are pretty, but that beauty masks its deadliness. According to the Missouri Botanical Garden, its leaves, fruits, and roots are all highly toxic whether eaten or just brushed up against if there's an open wound or abrasion. It's bad for grownups, but "the risk to children who do not understand the poisonous characteristics of all parts of this plant are huge," the Missouri Botancial Garden warns. 

While not as toxic as its cousin deadly nightshade, the pretty purple flowers and bright red berries on bittersweet nightshade are a tempting sight. However, the Midwest Invasive Species Information Network (MISIN) reports, "All parts of the plant are toxic." Those berries are poisonous to pets and can be deadly to children, so it's best to keep them out of the garden. "Use gloves and/or protective gear when handling plant," MISIN suggests.

These pretty lacy flowers (Cicuta douglasii) are part of the carrot family and look like wild parsnips or carrots, but they are far from edible. "Water hemlock is the most violently toxic plant that grows in North America," the USDA notes. Water hemlock has a toxin called cicutoxin that even in small amounts can trigger violent seizures that lead to cardiac arrest and death.

Another carrot cousin is giant hogweed, which has enormous blooms that look a bit like Queen Anne's lace on steroids. According to West Virginia University, the blooms are so pretty, and the 15-foot-tall plants so striking, that they were originally introduced to North America as ornamental plants. Don't plant them, though, as just one touch of the sap can cause severe skin irritation, burns, scarring, and blindness. If you spot giant hogweed in your garden, do not touch the plant or attempt to remove it yourself. Instead, call your county's environmental agency immediately.

Pokeweed, which is also known as poke root and pokeberry, is a confusing plant. While the properly prepared, boiled three times, tender spring leaves of this plant are the main ingredient in poke sallet, a fixture of Southern cuisine, the plant is truly toxic. Chefs preparing the pokeweed know that if they aren't careful, symptoms like vomiting, diarrhea, convulsions, and rapid heartbeat can quickly follow cooking. There's no doubt that the full-grown pokeweed with its shiny berries, magenta stems, and delicate white flowers from root to leaves is harmful, invasive, dangerous, and difficult to eradicate. Poke sallet is great, but we're leaving it to the pros and sticking to poke cake.

You'll be forgiven for not realizing that oleander, specifically Nerium oleander, is toxic, because the woody little shrub is a common sight in suburban landscapes due to its abundant, fragrant white, pink, red, or purple flowers. Despite its prettiness, it is extremely toxic due to a poisonous substance it produces that can cause heart arrhythmia, difficulty breathing, and cardiac arrest. It's bad for humans and animals, including dogs.