Poison Ivy

The characteristic three-leaflet structure of poison ivy stands as a warning signal. Poison ivy produces resins that cause an allergic reaction in most people and direct contact with the plant is not required for irritation to occur. Indirect contact through contaminated clothing or animals or with smoke from the burning plant will also produce symptoms.

Scott Camazine/Photo Researchers, Inc.

Poison Oak

Poison oak, a variety of Rhus toxicodendron, can be found growing in North America as short shrubs or climbing vines. Contact with the oily substance on the surface of its three shiny leaflets produces an itching, burning, and blistering reaction.

Renee Lynn/Photo Researchers, Inc.

Mushroom and Toadstools

Information On Mushrooms

Common Laburnum

Common laburnum is also known as golden chain, named for its hanging clusters of small, yellow blossoms, which may be as long as 38 cm (15 in). It is widely cultivated throughout the world despite the fact that all parts of the tree are poisonous.

D. Donadoni/Bruce Coleman, Inc.

Ling

Heather, or ling, is a bushy evergreen shrub growing to a height of 60 cm (24 in). The tiny pink or sometimes white flowers are numerous and borne in long terminal racemes. The scale-like leaves are only 1-2 mm long. Cultivated forms have foliage ranging from green, yellow, brown, and red to grey, white, and variegated.

Frithjof Skibbe/Oxford Scientific Films

Heather

Assorted cultivars of the representative genus of the heath family, Erica are seen here, together with Scotch heather (Calluna vulgaris), a species found over much of the cool-temperate area of the northern hemisphere.

Geoff Bryant/Photo Researchers, Inc.

Elephant Ears

The name "elephant ears" applies to eight species of giant rhizomatous herbs of the genus Colocasia whose leaves measure up to 1 m (40 in) in length. The taro, also known as elephant ears, dasheen, eddo, malanga, and yautia, is indigenous to tropical Asia. The large, edible, underground tubers are made into puddings, breads, and poi, and the massive leaves are eaten steamed or boiled. Both the tubers and the leaves must be cooked in order to remove poisonous calcium oxalate, which produces burning and swelling in the mouth and throat if eaten.

Mary M. Thacher/Photo Researchers, Inc.

Philodendron 

The philodendrons, a group of climbing plants native to tropical America, are commonly cultivated as houseplants for their attractive foliage.

Dorling Kindersley

Orange Natal Strychnos Tree 

Strychnos trees yield a varied crop of poison, medicine, and food. Aboriginal groups use the bark and leaves of one species to make curare, a paralysing poison used in hunting. Some species of the plant yield a quinine-like medicine, and the fruit of the natal orange variety is cultivated for commercial use.

Gregory G. Dimijian/Photo Researchers, Inc.

Wild Daffodil

The wild daffodil, a bulbous herb native to the eastern hemisphere, is widely cultivated for its bright yellow flowers. The daffodil is a common member of the genus Narcissus; plants of this genus are among the first to bloom, flowering in the early spring.

Dorling Kindersley

Common Poisonous Plants 

As many as one per cent of all plant species may be toxic to human beings and animals, their effects ranging from skin irritation to hallucinations, bone marrow destruction, paralysis, vomiting, and heart failure. Poisonous plants occur in all habitats and many cultivated gardens. Common varieties include (top, left to right) star-of-Bethlehem, deadly nightshade, poison ivy, poison oak; (bottom) yew, oleander, wisteria, and poison hemlock.

Dorling Kindersley/Marshall Black/Oxford Scientific Films/Deni Bown/Oxford Scientific Films/Renee Lynn/Photo Researchers, Inc.;G.A. Maclean/Oxford Scientific Films/Scott Camazine/Photo Researchers, Inc.