A tree 80 to 100 ft (sometimes more) high, with a trunk 3 to 5 ft through; bark deeply fissured and darkly coloured; young shoots light brown, not downy; buds egg-shaped to almost globose, narrowing at the top to a short, slender point, not resinous, but with pale brown scales edged with conspicuous whitish threads. Leaves in pairs, 21⁄2 to 41⁄2 in. long, persisting three to five years; straight, stiff, sharply but abruptly pointed; the margins are so minutely toothed as to be only just perceptible to the touch; leaf-sheath 1⁄2 to 5⁄8 in. long, persistent, with two grey curly threads at the top. The lower part of each year’s shoot is furnished with scale leaves only. Cones narrowly egg-shaped, 11⁄2 to 21⁄2 in. long, about 1 in. wide; scales unarmed; although usually solitary or in pairs, the cones are sometimes clustered as many as fifty or sixty together, and then much smaller. Bot. Mag., n.s., t. 558.
Native of Japan; introduced by John Gould Veitch in 1861. It is a very picturesque tree, with stiff, horizontal branches of often very unequal length, and although not likely ever to reach its natural dimensions in this country, well worth growing as an interesting and characteristic pine. The Japanese train it into many grotesque shapes. It is allied to P. nigra, but besides the marked difference in habit is easily distinguished by its broad, grey-white buds and shorter, stiffer leaves. In the wild it is a tree of maritime localities, and is used in Japan for fixing sand-dunes. Wilson saw some large trees growing by the shore in Shikoku whose trunks were washed by the waves in periods of flood tides or high seas.
Among the notable specimens of P. thunbergii are: Nymans, Sussex, pl. 1896, 62 × 6 ft (1970); Borde Hill, Sussex, seed sown 1890, 75 × 53⁄4 ft (1968); Lytchett Heath, Dorset, seed sown 1887, 65 × 71⁄4 ft (1966); Westonbirt, Glos., pl. 1880, 61 × 51⁄4 ft (1971).