Description from Flora of China
Pinus insularis Endlicher var. khasyana (Griffith) Silba; P. insularis var. langbianensis (A. Chevalier) Silba; P. kesiya var. langbianensis (A. Chevalier) Gaussen ex Bui; P. langbianensis A. Chevalier.
Trees to 30 m tall; trunk to 60 cm d.b.h.; bark brown, irregularly flaking; crown broadly domed; branchlets yellowish brown, shiny, aging to orange-brown, initially covered with scale bases (which are shed in 2nd or 3rd year), producing 2 or more nodes each year; winter buds red-brown, conical, slightly resinous. Needles 3 per bundle, slender, triangular in cross section, 10-22 cm × 0.7-1 mm, pliant, resin canals 3-6, marginal, base with persistent sheath 1-2 cm. Seed cones usually solitary or paired, ovoid, 5-6 × ca. 3.5 cm, persistent for many years. Seed scales narrowly suboblong, 2.5-3 × 1-1.5 cm; apophyses ± pyramidal, obviously transversely ridged; umbo small, ellipsoid, slightly protruded into a tiny recurved spine. Seeds black-brown, slightly appressed, ellipsoid, 5-6 × 3-4 mm.
Plateaus; 700-1200 m. SE Xizang, Yunnan [NE India, Laos, Myanmar, Philippines, Thailand, Vietnam]