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Pine Trees

The genus, Pinus, is the largest group of conifers, and it is made up of pine trees.  There are nearly 90 species of pine trees found throughout the globe, many of which have value for lumber, pulp, turpentine, oils, pine tar, chemicals, and other “naval stores.” Pine needles are found in groups of two, three, or five, encased in a sheath, also known as a “fascicle.” Most pine trees grow from a central terminal bud, and develop a single group of side branches along their truck, called a “whorl.”  Counting the number of whorls along the trunk of a pine tree is a good way to tell the age of the tree.

Pines have been split into two groups: soft pine and hard pine. The soft pines have a gradual transition from spring to summer wood, so that growth rings are not easy to spot; these trees have softer wood that is lighter in color. As a group, soft pines typically have five needles per bundle, but some have two.  These include eastern white pine, pinyon pine, sugar pine, and western white pine.The hard pines have a distinct transition between spring and summer wood, so that the growth rings are more distinct; the wood is normally harder and usually yellow.  Hard pines typically have two to three needles per bundle. Examples of hard pines include loblolly pine, pitch pine, shortleaf pine, red pine, longleaf pine, and ponderosa pine.

One of the most common members of the soft pine family found in Frederick County is the Eastern White Pine. This tree is the largest growing conifer found in the east, attaining a height of around 200 feet tall. Eastern white pines prefer well-drained soils with a sandy texture.  They can be found growing naturally in areas like Piney Mountain, north of Thurmont. Eastern white pine was one of the most important timbers utilized by colonists. These trees were prized by the British for ship masts, and some of the better examples were branded with the King’s Mark, meaning that they were reserved for the military. White pine were extensively planted on hillsides for erosion control projects in the 1960’s and 1970’s in Frederick County. Most of these plantations still persist today.  Pinyon pine are noteworthy in that they produce an edible nut as a fruit.  Pinyon pines are scattered around the semiarid sections of the south west. The sugar pine is a western tree that has the distinction as being the largest member of the pine family growing in North America, with some specimens growing to a height of 230 feet. Sugar pines are fast growing,  very wind firm, and long lived, with some trees attaining an age of 600 years. Sugar pine also have very large cones that range in size from 10 – 30 inches long.

The Virginia and Pitch pine are the most common hard pines growing in Frederick County, but sometimes a shortleaf pine can be found around Sugarloaf or College mountains. Likewise, one might see a Table Mountain pine tree in a real rocky area, such as the High Knob area of Gambrill State Park.  Loblolly pine is a common yellow pine found in southern Maryland and the Eastern shore. This tree is probably the most important timber-producing tree in the east. Loblolly pine growing in managed plantations can achieve a merchantable size in 35 years or so. Other important southern yellow pines include shortleaf pine, longleaf pine, and slash pine. The shortleaf pine has become somewhat rare throughout its range, and there are some concerted efforts to reestablish this tree to increase biodiversity. 

The longleaf pine is somewhat unusual in that it has a grass phase where it does not grow very tall, resembling blades of grass. During this period, the roots of the longleaf pine are growing.  Once the roots develop sufficiently, the tree will grow rapidly in height. The red pine is a dominant pine tree found in the lake states and to the north. Old growth red pine were cut in the Lake States and floated down rivers to a  sawmill in the 1800’s;  some of these trees sunk and were preserved under the water. Some of these large logs have been reclaimed recently from the watery depths to be used for lumber. The Ponderosa pine is a dominant tree found in the Rocky Mountains. One of the oldest living organisms found in the US is the Bristlecone Pine.  Some of these specimens are estimated to be 5,000 years old.  Compared to this, a 3,000 year old redwood is a relative new comer.

Article by Mike Kay, DNR Forester for Frederick County 
Photo of Sugar Pine Cone by David Barrow, Frederick County Forest Conservancy District Board
Photo of Bristol Cone Pine courtesy of www.Bosiatonight.com

Nature Note for 12/2/2018