Tree to 20m, 100cm in diameter with dark gray, scaly fissured bark; young branches glabrous, winter buds silvery white, scales persistent for 2-3 years; leaves 2 in a fascicle, rigid, dark green, 9- 14cm × 1.5mm; pollen cones cylindlic, 1.5 cm long, seed cones conic-ovoid, 6mm long, scales reddish, mature seed cones 50-60 scales, 45- 60mm × 30-40mm, the scales cuneate, the exposed part flatdsh, umbo apex blunt, seeds oval, 7-8mm long, darkish, wing lancelolate and mucronate, gray-brwon, cotyledons (4)6(8), seed maturity Oct of 2nd year 

2n=24
Pollination May
Seed maturity Sept
Distribution Japan Honshu to Kyushu; growing along the coast, Seaside and lowlands 

Taxonomic notes: Thick branches are split at the bottom is called f. multicaulis Uyeki.

<Japan Flora>

Japanese name: Kuro-matsu, O-matsu.

Tree with dark gray, scaly fissured bark; young branches glabrous; leaves 2 in a fascicle, straight, rigid, dark green, subterete, sharp- pointed, 7-15 cm, long, 1,5-2 mm. wide; cones short-peduncu­late, conic-ovoid, 4-6 cm. long, the scales cuneate, the exposed part flattish, with a small depressed mucro at the center.  Seaside and lowlands; Honshu, Shikoku, Kyushu; common. s. Korea.

<China Flora>

http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200005368

Cultivated in cities, used for afforestation on mountain slopes; to 1400 m. Beijing Shi, Hubei (Wuhan Shi, Yingshan Xian), Jiangsu (Nanjing Shi), Jiangxi, Liaoning, Shandong, Yunnan (Kunming Shi), Zhejiang [native to Japan, Korea]