北美短叶松 bei mei duan ye song

Trees to 25 m tall; trunk straight or crooked, to 0.6 m d.b.h. in native range; bark orange- or red-brown, scaly; crown irregularly rounded or flat topped; branchlets orange-red or red-brown, aging gray-brown, slender, rough; winter buds red-brown, ovoid, resinous. Needles 2 per bundle, yellow-green, twisted, 2-5 cm × 1-1.5(-2) mm, stomatal lines present on all surfaces, fine, base with semipersistent sheath 3-6 mm, margin finely serrulate. Seed cones upcurved, nearly sessile or shortly pedunculate, tan to pale brown or greenish yellow, ovoid when open, asymmetric, 3-5.5 cm, maturing in 2 years, then soon shedding seeds or often long serotinous and shedding seeds only with age or after fire. Apophyses mostly depressed but increasingly mamillate toward outer part, basal of cone; umbo depressed, sunken centrally, small, unarmed or with a small, reflexed apicula. Seeds brown or nearly black, compressed obovoid, oblique, 4-5 mm; wing 1-1.2 cm.

Cultivated. Beijing Shi, Heilongjiang (Harbin Shi), Henan (Jigong Shan), Jiangsu (Nanjing Shi), Jiangxi (Lu Shan), Liaoning, Shandong [native to N North America]