All parts of the evergreen spindle are considered toxic if ingested in large quantities. Symptoms can range from mild to life-threatening including vomiting, weakness, diarrhea, chills, convulsions, and coma. Since these plants are commonly used as ornamental hedges, you should be mindful of any children who may encounter the plant, be attracted by its colorful leaves and flowers, and may be tempted to eat them.

The castor bean is important for its oil which is used as a lubricant, biodiesel ingredient, and rodent repellent, among other applications. The plants are now commercially planted globally, with India producing nearly 75% of the world's castor oil. Castor beans cannot be eaten because they contain a potent poison that's released if the seed is broken.

Henbane is a poisonous annual or biennial plant that is native to the Mediterranean. The plant is entirely covered with greasy hairs. Its seeds spread from mid-spring to early fall.

Smoketree is a deciduous tree native to Southern Europe and Central China. The flowers of the smoketree are pinkish-purple and long-lasting. They grow in clusters along branches and give a smoky appearance to the tree when in bloom. In China, they are used as important fall decorations due to their foliage turn bright red in the fall.

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.

Sun spurge (Euphorbia helioscopia) is a winter annual that grows along the ground in a variety of locations from gardens to wastelands. It features distinctive red colored stems with toothed leaves that emit a toxic milky sap when cut or torn. Pale yellow flowers bloom from spring to summer and give way to fruit. This plant is considered a weed.

Bearded iris is known to cause contact dermatitis in some individuals. The most commonly reported symptom is minor skin irritation, typically lasting only a few minutes. This can result from contact with the seeds, roots, or sap of this plant. Furthermore, all parts of bearded iris are toxic when ingested, especially the roots. Symptoms typically including minor or moderate burning sensations, nausea, vomiting, abdominal pain, diarrhea, and fever. This plant is most often encountered in a garden context, where it is planted as an ornamental.

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.

Although its berries look juicy and tempting, the fruits and the root of pokeweed are toxic and should not be eaten. Pokeweed is considered a pest species by farmers but is nevertheless often grown as an ornamental plant. Its berries can be made into pokeberry ink as well.

Many species within the Cycas revoluta genus are highly toxic to dogs - if you suspect your dog has ingested any part of a sago palm plant, you should contact a vet immediately. The Sago palm is a very common ornamental and is the most common culprit. These plants contain high concentrations of the cycasin toxin, which is found throughout their structures but is most concentrated in their seeds. Ingesting even a small amount of cycasin can cause vomiting and diarrhea. Larger amounts can cause damage to the intestines and liver, coma, or death.

True to this plant's reputation, consumption of jerusalem cherry 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.

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.

All parts of the persian cyclamen contain toxins that are extremely hazardous to dogs, with the highest concentration in their tubers. Use caution if your dog is in a yard where persian cyclamen is found, especially if they enjoy digging. Symptoms range from lethargy to coma, and immediate veterinary care is needed to pump the canine's stomach to void the body of the toxin.

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.

Mexican lily (Hippeastrum reginae) is a plant species native to Venezuela, Bolivia, Peru and Brazil. Historically, mexican lily has been valued for its blossoms and has been the subject of still life paintings. This species was discovered by famous naturalist Carl Linnaeus in 1759.

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.

Oleander is moderately to highly toxic to humans – instances of ingestion, or physical contact with this plant's sap, should be immediately addressed by medical professionals. While fatal cases of oleander poisoning are very rare, they are possible. All parts of this plant are toxic if ingested. Physical contact with the plant's sap, which is found throughout the plant and is more likely to be exposed if the plant is cut or damaged, may cause dermatological symptoms, including redness and itchiness of the skin. Symptoms following ingestion include low blood pressure, lethargy, an irregular heartbeat, blurred vision, confusion, diarrhea, vomiting, dizziness, fainting and, in extreme cases, death. Be mindful of curious children, as oleanders are an extremely common ornamental plant cultivated in gardens and parks around the world.

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.

Durian (Durio zibethinus) is a tropical plant from Southeast Asia. It bears large, spiny, edible fruit which has become a major export crop of the region. The fruit is best known for its pungent smell, which provokes opposing reactions, ranging from near-addiction to revulsion. In some areas, it has even been banned from public transport and hotels.

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.