Trees to 21m; trunk to 0.6m diam., straight or more often crooked, commonly with adventitious sprouts; crown becoming ragged, thin, often broadly rounded or flat. Bark red-brown, irregularly furrowed and cross-checked into rectangular, flat, scaly plates. Branches spreading to ascending; twigs stout, orange- to yellow-orange, frequently glaucous, aging darker. Buds ovoid to narrowly ovoid, red-brown, 1--1.5(--2)cm, resinous. Leaves 3 per fascicle (to 5 in adventitious or disturbed growth), spreading to ascending, persisting 2--3 years, (12--)15--20(--21)cm ´ 1.3--1.5(--2)mm, slightly twisted, tufted at twig tips, straight, yellow-green, all surfaces with fine stomatal lines, margins serrulate, apex acuminate; sheath 1--2cm, base persistent. Pollen cones cylindric, to 30mm, yellow-brown. Seed cones maturing in 2 years, in some populations beginning to shed seeds then but more often variably serotinous, long-persistent, often whorled, symmetric, ovoid to lanceoloid before opening, broadly ovoid to nearly globose when open, 5--8cm, pale red-brown to creamy brown, sessile or on stalks to 1cm, scales with dark red-brown border on adaxial surface distally; apophyses slightly thickened, low, rhombic, low cross-keeled; umbo central, low-conic, with short, weak prickle, sometimes unarmed. Seeds ellipsoid, oblique at tip, somewhat compressed; body 5--6mm, pale brown, mottled darker or nearly black; wing to 20mm. 2 n =24. Flatwoods, flatwoods bogs, savannas, and barrens; 0--200m; Ala., Del., Fla., Ga., Md., N.J., N.C., S.C., Va. Pinus serotina is fire successional and sprouts adventitiously after crown fires. It is part of a distinct forest type including Taxodium distichum (Linnaeus) Richard, Nyssa biflora Walter, Magnolia virginiana Linnaeus, Persea sp., and Ilex sp. Of good form when protected from fire, P . serotina then much resembles P . taeda , with which it hybridizes naturally. It is of increasing importance as pulpwood.
Tree to 15(25) m; terminal buds very resinous; lvs in 3's, dark green, flexible, 15-25 cm; cones divergent or somewhat reflexed, globose-ovoid, 4-6 cm, usually persistent and remaining closed for several years; apophysis thickened, the umbo conic, with a straight or reflexed spine ca 1 mm; seeds ca 2.5 cm. Swamps and wet soil, chiefly on the coastal plain; Fla. to se. Md. and s. Del., and reported from s. N.J.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.