Poisonous Plant, any plant that causes serious illness or death if eaten. The term also is applied to plants such as poison ivy, poison oak, and poison sumac, which cause skin irritation when touched; and to plants such as coca and hemp, which have dangerous effects when chewed or smoked.

Deadly nightshade,Deadly nightshade, or belladonna, is a poisonous plant.

Thousands of plant species are poisonous, to some extent. Many contain alkaloids, such as strychnine. Others contain hydrocyanic acid, oxalic acid, or selenium. The poison often is concentrated in roots, leaves, fruits, or bark. Some poisonous plants are dangerous only in certain seasons. Plant poisons often are used as pesticides or, in controlled amounts, as drugs.

Some poisonous plants
NamePoisonous parts
Aconite (Monkshood) Flowers, leaves, roots
Azalea Entire plant
Belladonna Entire plant, especially berries
Castor bean (Castor-oil plant) Seeds
Chinaberry Berries
Daphne Bark, berries
Death camas Bulbs
Foxglove Entire plant
Gelsemium (Jessamine) Entire plant
Hyacinth Bulbs
Jimson weed (Datura) Entire plant
Mistletoe Berries
Mountain laurel Entire plant
Mushrooms, poisonous Entire plant
Narcissus Bulbs
Nightshade Entire plant, especially unripe berries
Oleander Entire plant
Poison hemlock Leaves, roots, seeds
Potato Green parts, spoiled tubers
Rhododendron Entire plant
Rhubarb Leaves
Tobacco Leaves
Water hemlock (Cowbane, Snakeroot) Roots, young leaves
Yew Bark, needles, seeds