Friday, July 13, 2012

Pines of the Eastern United States

For those interested in trying to learn the species of trees that they find around them, the members of the genus Pinus, the Pine trees, are perhaps some of the more simple in the Eastern United States.

These gymnosperms are unique insofar as their needles grow in bundles, or groups, which immediately help to distinguish one species from another.  Spruce and Fir, while superficially resembling Pine, and belonging to the same family of plants, Pinaceae (which includes pine, spruce, fir, cedar, hemlock), have single needles growing from their stems.  The image below gives you an idea of what these bundles look like up close:
File:Pinus sylvestris Sturm01.jpg
Notice the needles on ths botanical plate of a Scotch Pine (P. sylvestris) come off the stems in pairs of two -- these are the bundles referred to below.

To identify a pine tree, a knowledge of their range certainly helps, but then simply narrow your options based on the number of needles per bundle and needle length.  If needed, the cone can be a helpful indicator, as, for example, with the massive spine-covered cone of the Mountain Pine (P. pungens) of the Appalachians.  Perhaps the easiest to identify, the White Pine (P. strobus), the state tree of Maine, is immediately distinctive with not only its color and shelf-like appearance, but its fives needles per bundle.  Now for the species that you might find in the Eastern United States, with common introduced species with an * :


Pine Species                          Bundle #     Needle length        Cone length

Two in Bundle Species

Jack Pine (Pinus banksiana)               2                      ¾ -1½”                        1¼-2½”

Sand Pine (Pinus clausa)                    2                      2-4”                             2-3½”

Shortleaf Pine (Pinus echinata)          2 or s. 3           2¾-5”                          1½-3”

Slash Pine (Pinus elliottii)                   2 and 3           5-11”                           2½-6”

Spruce Pine (Pinus glabra)                 2                      1½-4”                          1-2½”

Austrian Pine (Pinus nigra)*               2                      3-6”                             2-3”

[Table] Mountain Pine (P. pungens)   2                      1¼-3”                          2-4”

Red Pine (Pinus resinosa)                   2                      4-6½”                          1½-2½”

Scotch Pine (Pinus sylvestris)*            2                      1½-3”                          1¼-2½”

Virginia Pine (Pinus virginiana)         2                      1½-3”                          1½-3”

 File:Pinus virginiana.jpg
Virginia Pine (Pinus virginiana)


Three in Bundle Species

Longleaf Pine (Pinus palustris)           3                      8-18”                           6-10”

Pitch Pine (Pinus rigida)                     3                      3-6”                             1-3”

Pond Pine (Pinus serotina)                 3                      4-8”                             2-3”

Loblolly Pine (Pinus taeda)                3                      5-9”                             3-6”

 File:Loblolly Pines South Mississippi.JPG
Loblolly Pine (Pinus taeda)


Soft Pines

Eastern White Pine (Pinus strobus)    5                      2-5”                             3-8”

File:Pinus strobus trees.jpg
White Pine (Pinus strobus)

Sources: National Audubon Society Field Guide to North American Trees, Eastern Region by Little; and Eastern Trees by Petrides.

For further information, check out this web resource: http://www.conifers.org/pi/Pinus.php

Live well!

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