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.

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.

Brazilian peppertree (Schinus terebinthifolia) is a flowering plant native to South America that is related to the cashew. Brazilian peppertree is widely cultivated as a houseplant in regions without frost. The plant can cause skin irritation in people with sensitive skin.

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.

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.

Devil's-backbone (Euphorbia tithymaloides) is a succulent species of spurge native to North and Central America. It has been planted in gardens since the 17th century and valued for its unique appearance and its habit of attracting hummingbirds. However, nearly all parts of this species are toxic and should not be consumed.

Golden dewdrops (Duranta erecta) is an ornamental sprawling shrub commonly found in subtropical and tropical gardens all over the world. Its gentle purple blossoms are often visited by butterflies and hummingbirds. Golden dewdrops is considered a weed in Australia, South Africa and certain parts of East Asia.

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.

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.

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.

African Milk Bush is rarely cultivated in the United States but is found growing in tropical Africa. The slow-growing succulent produces branches from the base, each one filled with a milky sap. The sap is poisonous is ingested and is also a skin irritant.

As a plant with beautiful flowers, tree tobacco should be planted with caution due to its high toxicity to both humans and animals through ingestion.

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.

The calla lily is a well-known ornamental plant with several cultivars receiving the Royal Horticultural Society's Award of Garden Merit. The most calla lily cultivars include 'Crowborough', 'Green Goddess', 'Pink Mist', and 'Red Desire'. They are popular as a cut flower or a rhizomatous herb in warm gardens.

The crown Flower has beautiful flowers that are used to make leis and were a favorite of the last queen of Hawaii. The outer petals of this flower curl back, and reveal what looks like a crown inside. The sap of this plant may cause skin irritation and can be considered toxic.

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.

Coral bean (Erythrina herbacea) is a low shrub or small tree species with red tubular flowers that appear on the tall stalks in the spring. Late in the summer the pods mature by turning black and splitting open to reveal scarlet-colored seeds. Coral bean seeds are extremely poisonous.

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.

Sprenger's asparagus fern (Asparagus aethiopicus) is a fern species native to South Africa. Despite its common name, this plant is not a true fern by taxonomy. Sprenger's asparagus fern is generally considered to be an invasive species. The common name was established by Carl Ludwig Sprenger who popularized cultivating sprenger's asparagus fern as an ornamental plant.

Sea daffodil (Pancratium maritimum) is a bulbous perennial species native to the Canary Islands, the Mediterranean region, and the area surrounding the Black Sea. The sea daffodil grows on beaches and coastal sand dunes. This species is often cultivated as an ornamental plant and requires full sunlight and well-drained soil to grow well.