Description from Flora of China
Pinus rigida Miller var. serotina (Michaux) Loudon ex Hoopes.
Trees to 21 m tall; trunk to 0.6 m d.b.h. in native range, usually with adventitious sprouts; bark red-brown, irregularly furrowed into oblong, flat, scaly plates; crown often rounded or flat; branchlets orange- or yellow-brown, often glaucous, stout; winter buds red-brown, ovoid or narrowly ovoid, 1-1.5 (-2) cm. Needles tufted at branchlet tips, 3 (or 5 in adventitious or disturbed growth) per bundle, slightly twisted, (12-)15-21 cm × 0.3-1.5(-2) mm, stomatal lines present on all surfaces, fine, base with persistent sheath 1-2 cm, margin serrulate, Seed cones whorled, sessile or pedunculate (when peduncles to 1 cm), pale red-brown or creamy brown, broadly ovoid or globose when open, 5-8 cm, maturing in 2 years, late dehiscent. Seed scales with dark red-brown border adaxially distally; apophyses rhombic, low cross keeled; umbo with a short, weak prickle, sometimes unarmed. Seeds pale brown, mottled darker or nearly black, somewhat compressed, ellipsoid, 5-6 mm, apex oblique; wing to 2 cm.
Cultivated. Jiangsu, Jiangxi, Zhejiang [native to SE United States]