USA Trees - Silohouttes Tour
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Species Hierarchy 
Common name: SPRUCE - WHITE
Scentific name: PICEA GLAUCA


Species Info:

This lifeform is found north of the Mason Dixon line in North America.

White Spruce (Picea glauca - older literature, Picea canadensis) is found coast to coast in Canada and widely in Alaska. This species avoids the warmer coastal areas of the Pacific Northwest. It extends into the United States in several places such as northern Wisconsin and Minnesota. It is usually found near water and typically grows up to 70 feet tall, although older records indicate it can grow up to 110 feet tall. The needles are less than one inch long, and generally are located on the upperside of the branch. The cones are less than 2.5 inches long.

Spruces (Genus picea) are found in the colder climates of the Northern Hemisphere.  These are a group of Gymnosperms that have stiff evergreen needles that grow singly along the branches.  The cones also hang. There are about 40 species in this genus worldwide.  China is blessed with about eighteen species. Seven species of spruces are native to North America,  and there is also a European species (Picea abies) that has become established in North America.   Because of  their beauty many species are frequently planted as ornamentals.

These seven native North American species are listed below. All seven species are pictured and discussed herein.  (*denotes  discussed and pictured herein).
           SPECIES                                                         LOCATION
  *Picea breweriana (brewer spruce)                NW USA (Local)
  *Picea engelmanni (engelmann spruce)      Rocky Mountains
  *Picea glauca (white spruce)                            Alaska & most of Canada
  *Picea mariana (black spruce)                        Alaska & most of Canada
  *Picea rubens (red spruce)                               New England & E. Canada
  *Picea pungens (blue spruce)                         Colorado & Adjacent
  *Picea sitchensis (sitka spruce)                      Coastal Pacific NW

The following brief summary might help separate the spruces of  the eastern USA.:

        White spruce (Picea glauca) is found across Canada and south into the United States to  Maine and northern New York, Michigan, and South Dakota.  The branches are horizontal and the tree has a pyramidal shape.  The needles are form 2.0 to 2.5 cm long and the cones are from 3 to 6 cm long.
       Red spruce (Picea rubens) is found in eastern northern North America.  This species has drooping branches and a pyramidal shape.  The needles are from 1.2 to 2.0 cm long and the cones are from 3 to 5 cm long.
       Black spruce (Picea mariana) is found from Maine west to Alaska.  This species has an unusual spire shape with relatively short branches.  The short needles are from .8 to 1.2 cm long and the cones are from 1.5 to 2.5 cm long.
      Norway spruce (Picea abies) has many named garden varieties.  This European species is a common ornamental.  The needles are from 1.2 to 2.0 cm long, and the very long cones are from 10 to 17 cm long.  The tigertail spruce (Picea polita) is native to the Orient.  It is an occasional ornamental with upwards spreading branches.   The needles are about 2.5 cm long and the cones are from 7-10 cm long.
  The blue spruce (Picea pungens) is native to Colorado,  but is very widely and very commonly planted as an ornamental.  The needles are from 2.5 to 3.5 cm long, and the cones are up to 8 cm long. The very unusual blue color of the needles will help identify this species.

Following is an incomplete list of some of the Eurasian Spruces (*denotes the species is discussed herein):

SPECIES                                                    LOCATION
*Picea abies(Norway spruce)            Northern Europe
*Picea meyeri                                           N. China
*Picea omorika                                        Balkans of Europe
*Picea polita                                             Orient
*Picea wilsonii                                          C&W China

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.


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