This lifeform is generally found west of the Continental Divide in North America The yellow color will help identify this lifeform. This lifeform is common in suitable environments.

Oregon-grape (Berberis aquifolium to Mahonia aquifolium) has been divided into two species. Berberis aquifolium, subspecies aquifolium, has become Mahonia aquifolium (Oregon-grape). Berberis aquifolium, variety repens, has become Mahonia repens (trailing Oregon-grape).

Shining or tall Oregon-grape (Mahonia aquifolium) is found from Humboldt County, California, to British Columbia and east into Idaho. It can grow to four feet tall.

Trailing Oregon-grape (Mahonia repens) is found from the Dakotas west to New Mexico and along the west coast from Inyo County, California, north to British Columbia. This prostrate plant is usually much less than eight inches high.

There are about 450 species in the genus Berberis.  Many species have been cultivated.  There are numerous named forms.  Kartesz asserts that eight species are now established in North America, which includes United States, Canada, Hawaii, Greenland, Puerto Rico and the U.S. Virgin Islands.

Barberry Family (Berberidaceae) is a small family of over 500  species. There are about 15 genera in this family. This family is well-represented in the Pacific Coast states of North America. There are 35 species in ten genera established in greater North America.

Ranales Order has been broken down into nineteen different  families. The water lilies, buttercups, magnolias, and other groups are included in this order. Large pretty flowers seem to be a common characteristic of this order.

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 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.

Plant kingdom contains a large variety of different organisms including mosses, ferns, and seed plants. Most plants manufacture their energy from sunlight and water. Identification of many species is difficult in that most individual plants have characteristics that have variables based on soil moisture, soil chemistry, and sunlight.

Because of the difficulty in learning and identifying different plant groups, specialists have emerged that study only a limited group of plants. These specialists revise the taxonomy and give us detailed descriptions and ranges of the various species.  Their results are published in technical journals and written with highly specialized words that apply to a specific group.

On the other hand, there are the nature publishers. These people and companies undertake the challenging task of trying to provide easy to use pictures and descriptions to identify those species.