Click on the thumbnail to see a slideshow of some examples of the bark.

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Brownish-gray bark of a longleaf pine approximately 30 years old.
Paper-like bark typically found on older longleaf pine trees.

(Detail of bark of virgin longleaf pine. Series: Forest Service collection. Photographer: Whitehead, H.E. Image number: 024466. Located at Gilburn Estate near Mount Pleasant, Florida. Photographed near Mount Pleasant, Florida. August 7, 1936. Courtesy of Florida Photographic Archives.)
Large, blocky plates of bark on a longleaf pine that likely exceeds 250 years in age, near Brooksville, FL. The shape of this bark is unusual, perhaps because few longleaf remain that exceed 250 years old.
The thick bark of a longleaf pine allows the tree to withstand frequent fires.
Charred bark on a longleaf pine tree. Over the next few months, this charred bark will slough off the tree. Thick bark on mature longleaf pine protects it from frequent fires.
A few years after the last fire, most of the charred bark has sloughed off. Charring in the deeper furrows of the bark is a reminder of the fire history.
Fire has burned through the bark of this longleaf pine and is creating a scar. This generally happens infrequently.
Fire found a weak spot on the bark of this longleaf pine and created a fire scar in the tree. Although this may not kill the tree, it does weaken it with repeated burning. Resins underneath the bark are flammable and add to fire intensity.

(Forest Service collection. Image number: 024976. Photographed by H.E. Whitehead and HJM. Photographed near Mt. Pleasant, Florida. August 7, 1936. Florida Forest Service. Florida Photographic Archives.)
Scaley bark of a longleaf pine tree that normally would burn off in a fire. Instead, due to lack of fire, this bark has sloughed off and built up around the base of the tree.
Shallow holes created by an overambitious yellow-bellied sapsucker woodpecker punches through the protective bark of a longleaf pine. The resin running down the tree's face demonstrates the function that bark plays as an "outer skin". This white resin is quite flammable and will likely cause this tree to burn vigorously in the next fire. This degree of sapsucker activity is generally rare.
Two men shown working longleaf pine trees as part of the turpentine industry (a business no longer practiced in the U.S.). The man on the right is scraping the bark of the longleaf. The man on the left is collecting the white colored, sappy resin that oozes from the wound created by removing the bark.

(Image courtesy of Wilson Baker's Postcard Collection.)
Longleaf tree with two turpentine faces cut into the bark. The white colored, sappy resin running down the tree would have been collected and taken to a distillery and refined into tupentine products.

(Pine showing cut for turpentine, near Fort Meade. Image number: Rc14108. Notes: How pine trees are cut to gather resin for turpentine. This tree has a cut on each side and is flowing freely. Photographed on April 4, 1930. Courtesy of Florida Photograhic Archives.)
A historic picture showing fire burning an active turpentine catface. Old timers say that the resin on the face of th elongleaf tree (not protected by bark) burned "like gasoline". To prevent these catfaces from catching fire, trees were often raked around by tupentiners.

(LA Coe collection. Image number: Lc320. Date: 19--? Photographed in Florida. Gift, Norman La Coe; Gainesville, FL; 1975. Courtesy of Florida State Photograhic Archives.)
The bark of this longleaf pine near Gautier, MS is in the prces of healing wounds inflicted from a turpentine extraction operation completed a few decades ago. These distinctive wounds are often called catfaces. Note the catface is no longer bleeding sappy resin, typically the cause for turpentine operations on a tree to cease.
Even though turpentine operations had ceased in this longleaf stand in Southern Pines, NC decades ago, evidence shows the unprotected catface of this old-growth tree allowed it to catch fire recently.
This longleaf specimen near Brooksville, FL had catfaces on two sides of the tree that had not healed up all the way. With no bark to protect them, a fire burned all the way through the tree. Strangely, the tree was still very much alive.

 

Longleaf Pine Bark

On young longleaf pine, the bark appears brownish gray in color and is deeply furrowed.  As the tree ages the furrows become shallower and the color assumes an orange-brown shade.  Also, as the tree ages the exterior scales appear more papery.  The thick bark of longleaf pine generally protects the trees from the frequent surface fires that occur in the area.  Scaly bark also tends to slough off during a fire.  Generally, the soot of past fires can be viewed in the bark furrows.  Occasionally, however, fires may find a weak spot and burn through the bark.  From then on, the bleeding of resin from this wound allows future surface fires a great advantage and over time a noticeable fire scar may develop.  A large fire scar may weaken (or perhaps kill) a longleaf pine tree.  Nonetheless, fire scars make excellent nesting sites for animal such as bluebirds.

It is not uncommon to find many insects (centipedes, spiders, ants, etc.) seeking refuge under the bark of longleaf pine trees.  Because of this rich food source, many species of birds such as the white-breasted nuthatch, brown creeper and red-cockaded woodpecker scramble up and down the tree, peeling off scales of bark in search of insects.  Some reptiles or amphibians like the barking tree frog or pinewood's tree frog take a more passive approach to hunting food and simply wait on the bark for food to come to them.