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.

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.

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.

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.

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.

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.

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 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 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.

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.

Chilean jasmine (Mandevilla laxa) is a flowering plant species that grows best in full sunlight and well-drained soil. Chilean jasmine is native to Chile and Argentina. This species produces masses of heavily-scented white flowers in the summer months, which smell like vanilla.

Blue potato bush (Lycianthes rantonnetii) is an evergreen shrub that was once considered to be part of the nightshade family. It is native to South America, but it is also cultivated in many gardens around the world for its vibrant purple-blue flowers which mature into bright red berries.

Eucalyptus trees are valued for their fast growth, good quality timber and pulpwood, but river red gum can be toxic to humans and animals due to its essential oil content.

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.

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.

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.

Evergreen azalea are members of the Rhododendron genus, all of which contain varying levels of a toxin known as Grayanotoxin in all tissues. Physical contact can cause a rash in sensitive people, the pollen can irritate mucus membranes, and ingesting it can cause nausea, vomiting, arrhythmia, low blood pressure, and hallucinations in humans. Grayanotoxin is so strong that even the amounts contained in honey made from Rhododendron pollen can have negative effects.

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.

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.

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.