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.

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.

Spanish broom is a deciduous shrub native to the Mediterranean, West Asia, and North Africa. Fragrant yellow pea-like flowers cover the shoots in late spring and summer. It is cultivated for its ornamental value and is used for flavoring and essential oil extraction.

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.

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.

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.

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.

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.

Sweet pea is a staple of flowering climbers and has been since the Victorian era. The sweet pea, which uses tendrils to climb when correct supports are available, grows to a height of 1.02 m – 2 m. The highly fragrant flowers are purple when found in the wild, but domesticated cultivars can be found in nearly every color.

Deadly nightshade or Atropa belladonna is true to its name; this plant, including the foliage, roots, and pretty blueberries, is extremely toxic and can cause death. It is especially toxic to small children, but also can be lethal for animals if ingested.

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.

Creeping buttercup can be severely toxic to dogs; you should seek immediate veterinary attention if you believe your dog has eaten or come into contact with a plant of this type. All parts of these plants contain ranunculin, a toxin that is poisonous when swallowed and also can irritate skin, causing redness or itch. Ingestion symptoms ranging from excessive drooling, vomiting, diarrhea, weakness, and loss of appetite to paralysis, seizures, jaundice, spasms, collapse, or even death.

Smallflower Buttercup can be severely toxic to dogs; you should seek immediate veterinary attention if you believe your dog has eaten or come into contact with a plant of this type. All parts of these plants contain ranunculin, a toxin that is poisonous when swallowed and also can irritate skin, causing redness or itch. Ingestion symptoms ranging from excessive drooling, vomiting, diarrhea, weakness, and loss of appetite to paralysis, seizures, jaundice, spasms, collapse, or even death.

As the name infers, the poison hemlock is a highly poisonous plant and has been known to intoxicate a variety of livestock. The leaves are similar to carrots and parsley, fooling most herbivores into consuming it. Poison hemlock can be lethal when ingested.

Woodland horsetail (Equisetum sylvaticum) is a perennial plant species native to North America and Eurasia. Woodland horsetail grows in swampy forest, open woodlands, and meadow areas. This species is considered one of the most attractive species of horsetail.

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.

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.

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 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.

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.