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.

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.

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.

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.

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.

Cow parsnip (Heracleum sphondylium) is a species of flowering perennial herb related to parsley and fennel. Its specific epithet, "sphondylium," means "vertebrate," and references its segmented appearance. This species produces extremely large amounts of nectar and thus attracts many bees.

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.

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.

American elder (Sambucus canadensis) is a North American native deciduous shrub with enormous inflorescence of grouped small white flowers and dangling bunches of mauveine berries. When cooked, the fruits can be added to pies, pancakes, and jellies. Wine can also be produced from its flowers and fruits. The bushy leaves and arching branches attract wildlife, providing nesting space for birds.

Common barberry is a shrub with unpleasant-smelling flowers and red berries. The flowers can be used to create yellow dye while the berries have culinary and medicinal uses in Iran and medicinal use in China that dates back 3,000 years. Despite this, common barberry can be a host to wheat rust that is highly damaging to grain crops in America.

All parts of common columbine, including the stem, leaves, flowers, and seeds, are toxic when they are ingested raw. Contact with the plant's sap may also lead to dermatitis (skin irritation and inflammation). The symptoms from common columbine poisoning are likely to cause only mild to moderate effects, but the symptoms are not well-known, since there are few documented cases of it. Adverse effects are most likely to occur from accidental ingestion.

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.

Pink rain lily (Habranthus robustus) is a plant species native to Brazil. Pink rain lily blooms four to six times in a single summer. This species has blossoms that often bloom right after a rainstorm. Pink rain lily grows equally well in shaded areas and areas with plenty of sun.

Christmas rose (Helleborus niger) is a flowering evergreen perennial plant that is often grown in ornamental gardens because it flowers in the winter. Planting christmas rose is particularly common in cottage garden styles. In the wild, christmas rose grows in Germany, Austria, Switzerland, Italy, and Croatia. This plant is considered somewhat difficult to grow and requires moist, alkaline-rich soil.

Henbane is a poisonous annual or biennial plant that is native to the Mediterranean. The plant is entirely covered with greasy hairs. Its seeds spread from mid-spring to early fall.

The golden chain tree is used as an ornamental in gardens and patios. It gets its name from the cascading yellow flowers that bloom in late spring. The lumber can be used for cabinetry, inlay work, and musical instruments. The flexible branches also used to be important for making bows. The golden chain tree is toxic in its entirety and can be fatal 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.

Mediterranean spurge (Euphorbia characias) is a flowering evergreen shrub that blooms from spring to early summer. Its nectar glands attract many pollinators, including bees and butterflies. This species grows well in dry or well-drained soil and has become a popular choice for desert gardens.

Alpen rose is a small evergreen shrub native to high mountain ranges of Europe, where it grows on acidic soil above the tree line. It is renowned for its bell-shaped, pink, summer flowers. It is moderately toxic and should not be ingested.

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.