Wikipedia states: It is a pine native to the southeast United States, found along the coastal plain from eastern Texas to southeast Virginia extending into northern and central Florida. It reaches a height of 30–35 m (98–110 ft) and a diameter of 0.7 m (28 in). In the past, they reportedly grew to 47 m (150 ft) with a diameter of 1.2 m (47 in). The bark is thick, reddish-brown, and scaly. The leaves are dark green, needle-like, and occur in bundles of three. They are often twisted and are remarkably long 20–45 cm (7.9–18 in) in length. It is one of the two southeastern U.S. pines with long needles, the other being Slash Pine. The cones, both male pollen cones (staminate strobili) and female seed cones (ovulate strobili), are initiated 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 male cones 3–8 cm (1.2–3.1 in) long. The female (seed) cones mature in about 20 months from pollination; when mature they are yellow-brown in color, 15–25 cm (5.9–9.8 in) long, 5–7 cm (2.0–2.8 in) broad opening to 12 cm (4.7 in), and have a small but sharp downward-pointing spine on the middle of each scale. The seeds are 7–9 mm (0.28–0.35 in) long, with a 25–40 mm (0.98–1.6 in) wing. Longleaf Pine takes 100 to 150 years to become full size and can live to 500 years old. When young, they grow a long taproot, which is usually 2–3 m (6.6–9.8 ft) long; by maturity they have a wide spreading lateral root system with several deep 'sinker' roots. It grows on well-drained, usually sandy soil, often in pure stands. In northern Alabama, it sometimes occurs on clay soil. The scientific name meaning "of marshes" is a misunderstanding on the part of Philip Miller who described the species, from seeing Longleaf Pine forests with temporary winter flooding. Longleaf Pine is also known as Southern Yellow Pine or Longleaf Yellow Pine, and in the past as Pitch Pine (dropped as it caused confusion with Pitch Pine, Pinus rigida).

A source of pulp, timber, and turpentine. Extremely adaptable and common in the sandy or clay-sand ridges of Georgia. Useful in coastal landscapes, it adds texture and unique architecture to large scale plantings. Dark green needles, to 18" (9" in older trees), in tufts at ends of branchlets; hangs on to its cones (to 20") for as long as 20 years; native from Virginia to Florida and Mississippi