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.

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.

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.

True to this plant's reputation, consumption of turkey berry 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.

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.

Star of Bethlehem (Hippobroma longiflora) is a perennial, herbaceous plant whose blossoms look similar to jasmine flowers but are not fragrant. Produces a milky white sap that is highly toxic and irritating to the skin. Contact with the eyes can cause blindness. Avoid handling this plant with bare hands.

The heart of jesus plant has a name that implies purity, but it is actually toxic. Like other Caladiums, its sap is extremely irritating when eaten or even just applied to the skin. A painful, itchy rash breaks out on contact. That rash is essentially what a person who ingests it will experience as well, except inside of their mouths and all the way down their digestive tracts. Besides a great deal of pain and irritation, this causes severe nausea, excessive salivation, vomiting and diarrhea, and also significant swelling in many cases. Keep this plant away from children.

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.

Mexican fireplant is native to tropical America, but it has been naturalized in other tropical and subtropical regions in the world. *Euphorbia heterophylla* is a poisonous plant to humans and livestock. It contains a toxic milky sap which can cause strong skin irritation.

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.

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.

Asthma-plant (Euphorbia hirta) is a ground-hugging spurge weed whose branches can grow to 61 cm long. It blooms from summer through early fall, dying off after the first frost. A milky sap will seep from broken stems or leaves. It can be a nuisance weed that reproduces rapidly.

Hyssop-leaf sandmat (Euphorbia hyssopifolia) is a sandmat that’s indigenous to the southwestern part of the United States. A sandmat is a plant in the genus of Euphorbia that thrives best in deserts. Hyssop-leaf sandmat has a milk-white sap in its stem—just like the milkweed. It’s also known as hyssop spurge, eyebane, wart weed, and chicken weed.

The barbados nut (Jatropha curcas) plant is cultivated throughout the world for ornamental uses because of its rapid growth. Since cattle will not consume the leaves, it works very well as a living fence around grazing areas. Oil is extracted from the nuts and used as a torch fuel and burns so well that the fires are not affected by strong winds!

Palay rubbervine (Cryptostegia grandiflora) is a plant species that can grow to be 2 m tall when the plant is a shrub. When palay rubbervine is supported by other vegetation as a vine, it can reach up to 30 m in length. This species is native to Madagascar.

Matted Sandmat is an annual weed that grows flat along the ground into a matted form. It has a long tap root and hardy seeds, which make it difficult to eradicate. This plant’s sap can irritate the skin and is toxic.

Moth plant (Araujia sericifera) is a perennial vine native to South America. Moth plant has been introduced around the world. This species is used as a food source for monarch butterflies, although it is not their preferred food.

Rosary Pea is among the world's top 10 most poisonous plants. Ingesting a single seed of this plant can be fatal. However, these seeds are prized for making both jewelry and musical instruments.

Prostrate sandmat (Euphorbia prostrata) is a plant species native to tropical regions of North and South America and the central United States. Prostrate sandmat has spread all over the globe and is considered an invasive species. This resilient plant often sprouts up through cracks in asphalt on roadsides.