This lifeform is only found domesticated.

True firs (Genus Abies) are a group of Gymnosperms that have needles that grow singly from the branches.  The cones are upright on the branches.  There are about 50 species of firs worldwide and nine of them are native to North America. Two European species are also established in the United States.  The trees are popular as Christmas trees, and the wood is useful for wood pulp. Following is a list of the firs that are found in the United States (excluding the two natural hybrids):

    *Abies amabilis           Pacific Silver      West Coast of Canada
   *Abies balsamea       Balsam Fir          Central & East Canada
   *Abies bracteata        Bristlecone Fir   Local California
   *Abies concolor         White Fir              Rockies and California
   *Abies fraseri              Fraser Fir            Local Appalachian Mnts
    Abies grandis           Grand Fir             Pacific NW
   *Abies lasiocarpa    Subalpine Fir     Rocky Mountains
    Abies magnifica      California Red    Central California
    Abies procera          Noble Fir             Pacific Northwest
*denotes  discussed and pictured herein

North American Pine family contains many valuable species.

Pines and Spruces, etc. (Family Panacea) comprise a group of about nine genera and about 195 species found worldwide. The family is of tremendous economic importance for building lumber. This group is also one of the most predominant forms of vegetation on much of the earth's land area. There are several important genera in this family, including the Firs (Abies), Spruces (Picea), Pines (Pinus), and Douglas Firs (Pseudotsuga).

Conifers (Order Coniferae) is an important group of trees and bushes found throughout the world. Although very common in the forests everywhere, this group of plants has only about 520 species. They are characterized by having needles. Pine trees and spruce trees are typical examples of conifers.

Gymnosperms are a group of trees and bushes usually characterized by needles and the production of cones to support the seeds. Most species are evergreen. (The actual technical definition has to do with the method of producing the seed.)

There are over 600 species of Gymnosperms known to science. The largest genus in this group in terms of species is the Pine genus with about 120 species. The second most common genus is the Podocarpus genus which is normally a more tropical group than the Pines.

Kartesz lists 135 species as growing in greater North America, including Hawaii, Puerto Rico, and the Virgin Islands.

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.