Japanese Black Pine can reach the height of 40 m, but rarely achieves this size outside its natural range. The needles are in fascicles of two with a white sheath at the base, 7-12 cm long; female cones are 4-7 cm in length, scaled, with small points on the tips of the scales, taking two years to mature. Male cones are 1-2 cm long borne in clumps of 12-20 on the tips of the spring growth. Bark is grey on young trees and small branches, changing to black and plated on larger branches and the trunk; becoming quite thick on older trunks. Because of its resistance to pollution and salt, it is a popular horticultural tree. In Japan it is widely used as a garden tree both trained as Niwaki and untrained growing as an overstory tree. The trunks and branches are trained from a young age to be elegant and interesting to view. It is one of the classic bonsai subjects.