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.

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.

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.

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.

The bird of paradise is a bright, flowering plant. It is native to South Africa, where it is important to national culture, even being featured on the country's 50-cent coin. The bird of paradise has also become the official flower of Los Angeles in spite of its non-native status. In the wild, these flowers attract sunbirds as pollinators.

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.

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 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.

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.

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.

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.

Nerium oleander, colloquially known as oleander, is a shrub or a small tree, known for its majestic pink five-lobed flowers and deep green lanceolate leaves. Oleander is one of the most poisonous popular decorative garden plants, so it is advised to keep small children and pets away from it.

Plants of the Asclepias curassavica genus are extremely toxic to dogs—immediate veterinary attention should be sought if your dog has consumed anything of this type. Toxins are found in all parts of the plant. Symptoms of poisoning from bloodflower include weakness, dilated pupils, vomiting, and diarrhea. In more serious cases, these symptoms may progress towards difficulty breathing, an elevated heart rate, organ failure, coma, or death.

Glossy shower (Senna surattensis) is an evergreen, perennial tree that blooms year-round with golden-yellow flowers. It is also called Scrambled Eggplant, Sunshine Tree, or Golden Senna. It thrives in full sun and prefers well-drained soil. It is considered an invasive weed in Asia.

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.

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

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.

Opium poppy (*Papaver somniferum*) was first cultivated approximately 5,400 years ago by the lower Mesopotamians. The Sumerians called it “Hul Gil,” which means the “joy plant.” It is used in the production of medical painkillers. The tiny seeds are commonly added as a topping on bread buns, but most portions of the plant are toxic if eaten.

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 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.