longleaf pine

The bark is thick, reddish-brown, and scaly. The leaves are dark green and needle-like, and occur in bundles of mainly three, sometimes two or four, especially in seedlings. They often are twisted and 20–45 centimetres (7+3⁄4–17+3⁄4 inches) in length. A local race of P. palustris in a cove near Rockingham, North Carolina, have needles up to 24 inches (61 centimeters ) in length. It is one of the two Southeastern U.S. pines with long needles, the other being slash pine. The cones—female seed cones (ovulate strobili) and male pollen cones (staminate strobili)—begin to form during the growing season before buds emerge. Pollen cones begin forming in their buds in July, while seed conelets are formed during a relatively short period of time in August. Pollination occurs early the following spring, with the pollen cones 3–8 cm (1+1⁄4–3+1⁄4 in) long. The seed cones mature in about 20 months from pollination; when mature, they are yellow-brown in color, 15–25 cm (6–9+3⁄4 in) long, and 5–7 cm (2–2+3⁄4 in) broad, opening to 12 cm (4+3⁄4 in), and have a small, but sharp, downward-pointing spine on the middle of each scale. The seeds are 7–9 millimetres (1⁄4–3⁄8 in) long, with a 25–40 mm (1–1+5⁄8 in) wing. Longleaf pine takes 100 to 150 years to become full size and may live to be 500 years old. …

Before European settlement, longleaf pine forest dominated as much as 90,000,000 acres (360,000 km2) stretching from Virginia south to Florida and west to East Texas. Its range was defined by the frequent widespread fires that were lit by humans and occurred naturally throughout the southeast. In the late 19th century, these virgin timber stands were "among the most sought-after timber trees in the country." This rich ecosystem now has been relegated to less than 5% of its presettlement range due to fire suppression and clear-cutting practices:

As they stripped the woods of their trees, loggers left mounds of flammable debris that frequently fueled catastrophic fires, destroying both the remaining trees and seedlings. The exposed earth left behind by clear-cutting operations was highly susceptible to erosion, and nutrients were washed from the already porous soils. This further destroyed the natural seeding process. At the peak of the timber cutting in the 1890s and first decade of the new century, the longleaf pine forests of the Sandhills were providing millions of board feet of timber each year. The timber cutters gradually moved across the South; by the 1920s, most of the "limitless" virgin longleaf pine forests were gone. — Jerry Simmons, "ASLC Large Operation from Beginnings" In "pine barrens" most of the day. …

Longleaf pine is highly pyrophytic (resistant to wildfire) and dependent on fire. Their thick bark and growth habits help to provide a tolerance to fire. Periodic natural wildfire and anthropogenic fires select for this species by removing competition and exposing bare soil for successful germination of seeds. The lack of medium-tall trees (called a midstory canopy) leads to open longleaf pine forests or savannas. New seedlings do not appear at all tree-like and resemble a dark-green fountain of needles. This form is called the grass stage. During this stage, which lasts for 5–12 years, vertical growth is very slow, and the tree may take a number of years simply to grow ankle high. After that, it has a growth spurt, especially if it is in a gap or no tree canopy is above it. In the grass stage, it is very resistant to low intensity fires because the terminal bud is protected from lethal heating by the tightly packed needles. While relatively immune to fire at this stage, the plant is quite appealing to feral pigs; the early settlers' habit of releasing swine into the woodlands to feed may have been partly responsible for the decline of the species. Longleaf pine forests are rich in biodiversity. They are well-documented for their high levels of plant diversity, in groups including sedges, grasses, carnivorous plants, and orchids. …

Vast forests of longleaf pine once were present along the southeastern Atlantic coast and Gulf Coast of North America, forming savannahs and woodlands that covered large portions of the Coastal Plain. These forests were the source of naval stores – resin, turpentine, and timber – needed by merchants and the navy for their ships. They have been cutover since for timber and usually replaced with faster-growing loblolly pine and slash pine, for agriculture, and for development. Due to this deforestation and overharvesting, at its lowest point in the 1990s, only about 1.3 million hectares (3.2 million acres) of longleaf pine forest remained: roughly 5% of its original range. Although now replaced across most of its range by loblolly pine plantations, conservation efforts did slightly raise the area of longleaf forest cover to 2.3 million ha (5.6 million ac) by 2023. Despite its decline on the landscape, longleaf pine is available at many nurseries within its range; the southernmost known point of sale is in Lake Worth Beach, Florida. The yellow, resinous wood is used for lumber and pulp. …

The species epithet palustris is Latin for "of the marsh" and indicates its common habitat. The scientific name meaning "of marshes" is a misunderstanding on the part of Philip Miller, who described the species, after seeing longleaf pine forests with temporary winter flooding.