Plants can have flowers that are poisonous to both animals and humans. Adults know better than to eat flowers or other parts of plants that are not known food products. Children, pets and wild animals may try anything they can get near. Reactions range from mild discomfort to death, and gardeners have the responsibility to learn about flowers before they decide to add them to their landscaping plans. Plant poisonous flowers in a contained space where children and pets will not be able to investigate how tasty they are.
Coral plant (Jatropha multifida) is a member of the spurge family. All parts of the plant are poisonous if ingested. The sap causes skin irritation. The plant grows as a shrub or small tree, reaching a height between 6 and 20 feet. Leaves grow up to 12 inches wide and are dark green on top and whitish underneath. Bright red-coral flowers grow in flat topped clusters, blooming all year. Plant coral plant in full sun or light shade and a soil that is well-drained. The plant is hardy in USDA Zones 10 to 12.
Castor Oil Plant
Castor oil plant (Ricinus communis) grows as a shrub or small tree up to 40 feet tall and 15 feet wide. The plant produces palm-shaped purple or red-green leaves 12 to 30 inches across, growing on long red or purple stems. Small, green-white flowers grow in clusters from 8 to 18 inches long near the tips of the stems. Female flowers produce red-brown, egg-shaped seed capsules that house the beans. Place the castor oil plant in a place where it gets full sun and in a moist to wet soil. The plant is hardy in USDA Zones 8 to 11. All parts of the plant are poisonous and can be fatal, especially to young children.
Natal plum (Carissa macrocarpa) is a member of the dogbane family. All parts are poisonous, even the fruit until it is ripe. The plant is an evergreen shrub growing up to 20 feet tall. Oval-shaped, dark-green leaves measure 1 to 3 inches long. Fragrant, white, star-shaped flowers measure 2 inches across and produce a red berry 2 inches long that resembles a plum and has the taste of a cranberry. The tree has the capacity to produce flowers continuously throughout the year with both flowers and fruits on the tree at the same time. Plant natal plum in full sun and a sandy, well-drained soil. The plant is hardy in USDA Zones 9 to 11.