If either ingested or touched, dieffenbachia can cause negative reactions. The symptoms range from moderate to severe and can be dangerous if airways are blocked. Due to the calcium oxalate contained in this plant, its leaves and sap have toxic properties. When ingested, they can induce symptoms such as lip and tongue swelling, drooling, speech loss, and difficulty breathing; when touched, they can cause a painful skin rash or eye irritation. Since these plants are often found indoors as decorative plants, be careful when keeping them around small children. Always wear gloves when handling this plant.

All parts of common columbine, including the stem, leaves, flowers, and seeds, are toxic when they are ingested raw. Contact with the plant's sap may also lead to dermatitis (skin irritation and inflammation). The symptoms from common columbine poisoning are likely to cause only mild to moderate effects, but the symptoms are not well-known, since there are few documented cases of it. Adverse effects are most likely to occur from accidental ingestion.

Hyacinthus orientalis is one of the heralds of spring. The name common hyacinth comes from the Greek name Hyacinthus. According to Greek legend, Hyacinthus was admired by both Apollo and Zephyrus. Hyacinthus ended up being killed out of jealousy and a flower bloomed on the spot where his blood was spilled. Apollo named the flower after his lost love.

Creeping buttercup can be severely toxic to dogs; you should seek immediate veterinary attention if you believe your dog has eaten or come into contact with a plant of this type. All parts of these plants contain ranunculin, a toxin that is poisonous when swallowed and also can irritate skin, causing redness or itch. Ingestion symptoms ranging from excessive drooling, vomiting, diarrhea, weakness, and loss of appetite to paralysis, seizures, jaundice, spasms, collapse, or even death.

Wild daffodils have low-level toxicity when the leaves or bulbs are ingested. The bulbs, however, are the most toxic part of the plant. If the bulbs are ingested, symptoms may include vomiting, diarrhea, and excessive salivation. If a large quantity is consumed, convulsions, low blood pressure, tremors, and cardiac arrhythmias may occur. Poisoning is most likely to occur from accidental ingestion by children, as wild daffodils are grown in gardens around the world.

Striped barbados lily is perennial herbs with showy flowers but it contains toxic compounds, most notably alkaloids lycorine and tazetine, as well as calcium oxalate crystals.

True to this plant's reputation, consumption of potato can be extremely toxic to dogs, and warrants immediate veterinary attention. All parts of these plants contain several toxic substances which can cause loss of appetite, excessive drooling, vomiting, diarrhea, dilated pupils, confusion, behavioral changes, and weakness. In more severe cases, difficulty breathing, a lowered heart rate, coma, or even death may occur, so treat it as a medical emergency if your pet has come into contact with this plant.

Bird of paradise is generally considered non-toxic but can be poisonous when ingested in large quantities. Cases of poisoning are typically mild to moderate with symptoms including abdominal cramps, nausea, vomiting, and diarrhea. Cases of poisoning may be more serious in children. The fruit and seeds are considered to be the most toxic parts of the plant. The frequent use of this plant as a houseplant could be a factor in poisoning frequency. This plant can be mistaken for another more toxic species, Poinciana gilliesii, as they share the same common name, bird of paradise.

Woodland horsetail (Equisetum sylvaticum) is a perennial plant species native to North America and Eurasia. Woodland horsetail grows in swampy forest, open woodlands, and meadow areas. This species is considered one of the most attractive species of horsetail.

Old man's beard (Clematis vitalba) is a deciduous climbing shrub that will grow to 12 m tall. It blooms with fluffy flowers and fruits that have long silky strands that look like the wispy beard of an old man. This plant is a food source for a variety of moths. Often seen scrambling over hedgerows, it is considered a noxious weed, especially in New Zealand. Evidence suggests ancient Europeans made rope and baskets with old man's beard.

The golden chain tree is used as an ornamental in gardens and patios. It gets its name from the cascading yellow flowers that bloom in late spring. The lumber can be used for cabinetry, inlay work, and musical instruments. The flexible branches also used to be important for making bows. The golden chain tree is toxic in its entirety and can be fatal if eaten.

Hairy willowherb (Epilobium hirsutum) is a species of weed that is difficult to eradicate. It is not known to be toxic, but the sale of this plant or its seeds has been banned in some areas. This is because its dense, aggressive growth habits can crowd out and destroy other native beneficial plants.

Plants of genus Buxus are widely present around the world as а hedge or garden ornamental plants, but they contain alkaloids, most notably buxin, which are toxic to animals.

Greater creeping spearwort can be severely toxic to dogs; you should seek immediate veterinary attention if you believe your dog has eaten or come into contact with a plant of this type. All parts of these plants contain ranunculin, a toxin that is poisonous when swallowed and also can irritate skin, causing redness or itch. Ingestion symptoms ranging from excessive drooling, vomiting, diarrhea, weakness, and loss of appetite to paralysis, seizures, jaundice, spasms, collapse, or even death.

Dutchman's pipe is a hardy, deciduous vine that climbs trellises or walls and can provide privacy or shade with its dense, heart-shaped leaves. This vine grows small pipe-shaped flowers that give it its name. Dutchman's pipe attracts many swallowtail butterflies with its pretty little blooms.

Blackthorn (Prunus spinosa) is a large deciduous shrub species that is also commonly called a sloe. Blackthorn is indigenous to Europe, Asia, and Africa. In Britain, this species is used to make a liquor called sloe gin. In Ireland, its wood is made into walking sticks.

Black cohosh is toxic to mammals including humans and household pets, whereas birds help disperse the seeds without harm. Its bright berries are attractive to children, which can lead to serious problems.

Common yew is highly toxic to all animal species, including humans, dogs, cats, livestock and poultry, with all parts of the plant capable of causing death when consumed in large amounts.

A garden poppy that can escape as a scrambling weed across open fields, the common fumitory (Fumaria officinalis) produces flowers from early spring to late fall. In the past, it had been used as a folk medicine, but it is now known to be poisonous and should not be used in any home remedies.

Pontic rhododendron (Rhododendron ponticum) is a dense shrub species that is one of the most extensively cultivated Rhododendron species in western Europe. Pontic rhododendron is native to southern Europe and southwest Asia. This species is widely cultivated for ornamental purposes, and considered invasive in western Europe. Honey produced from the pollen of this species is poisonous.