This lifeform is generally found west of the Continental Divide in North America The pink color will help identify this lifeform. This lifeform is widespread, but not common.

Lyall's Rockcress (Arabis lyallii) is found from British Columbia south to California and east to Alberta, Montana, Wyoming, and Utah. This one to two foot plant has oblong entire basal leaves and multiple reddish purple flowers atop the stem.

Arabis genus (rock cress) is native to temperate Eurasia and temperate North America.   There are about 120 perennial and annual herbs in this genus.  Although the leaves can be toothed,  they are usually simple.  There were 78 species and 60 named subspecies growing in greater North America as of 1994.

Mustard Family (Cruciferae) is a very large family of mostly herbs. There are about 2,500 to 3,000 species usually organized into about 400 different genera. The family is important for food including brussels sprouts, cabbage, cauliflower, raddishes, mustard, and turnips. The family contains several weeds that are particularly troublesome to farmers in the genera Brassica and Barbarea. Modern botanists would like to change the name of this family to the Brassicaceae family. There are about 700 species arranged into about 100 genera in greater North America.

Rhoeadales Order includes the Poppies, Mustards, and mostly other non-woody groups of plants.

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.