Narrative

Poison Ivy (Rhus radicans or Toxicodendron radicans) is found widely in the United States and Canada from New England to the Pacific Northwest. This species normally occurs as either a bush or a vine. The leaves, in groups of three, gives a helpful warning that the plant is Poison Ivy. This plant upon contact with the skin can cause severe skin rash and painful itching in humans.

This lifeform is poisoness. This lifeform is widespread, but not common. This lifeform has chemicals that are dangerous to man and is poisonous.

This lifeform is widespread in North America.

Sumacs (genus Rhus) comprise about 200 species found in North America, South Africa, Asia, and Australia. These species generally have odd pinnately compound leaves. They are frequently shrubs or bushes, and occasionally become small trees. There are 13 species, two hybrids, and fourteen subspecies listed in the Kartesz list of greater North America, including the United States, Canada, Hawaii, Greenland, Puerto Rico and the U.S. Virgin Islands. Although some scientists place poison ivy and poison sumac in this genus, most authors now separate those species into the genus Toxicodendron. The Toxicodendron genus has an additional five species native to greater North America.

Cashew or Sumac Family (Anacardiaceae) contains about 800-900 species usually organized into seventy different genera. Included in this family are several poisonous plants like Poison Oak and Poison Sumac. Raw cashews are reportedly poisonous. There are 37 species arranged in 12 genera growing in greater North America.

Sapindales Order is a diverse group of mostly trees and shrubs.

Dicots (Dicotyledoneae Class) are the predominant group of vascular plants on earth. With the exception of the grasses (Monocots) and the Conifers (Gymnosperms), most of the larger plants that one encounters are Dicots. Dicots are characterized by having a seed with two outer shell coverings.

Some of the more primitive Dicots are the typical hardwood trees (oaks, birches, hickories, etc). The more advanced Dicots include many of the Composite (Aster) Family flowers like the Dandelion, Aster, Thistles, and Sunflowers. Although many Monocots reach a very high degree of specialization, most botanists feel that the Dicots represent the most advanced group of plants.

Seed plants (Phylum Embryophyta) are generally grouped into one large phylum containing three major classes: the Gymnosperms, the Monocots, and the Dicots. (Some scientists separate the Gymnosperms into a separate phylum and refer to the remaining plants as flowering plants or Angiospermae.)

For North American counts of the number of species in each genus and family, the primary reference has been John T. Kartesz, author of A Synonymized Checklist of the Vascular Flora of the United States, Canada, and Greenland (1994). The geographical scope of his lists include, as part of greater North America, Hawaii, Alaska, Greenland, Puerto Rico, and the Virgin Islands.

Kartesz lists 21,757 species of vascular plants comprising the ferns, gymnosperms and flowering plants as being found in greater North America (including Alaska, Hawaii, Greenland, Puerto Rico and the Virgin Islands.

There are estimates within the scientific world that about half of the listed North American seed plants were originally native with the balance being comprised of Eurasian and tropical plants that have become established.