Pinus contorta Loud.

A tree 20 to 30 ft in the wild, but taller in cultivation; bark of mature trees thick, roughly fissured; young shoots often curiously twisted, glabrous; terminal buds narrowly cylindrical, 3⁄4 to 1 in. long, resinous. Leaves in pairs, 11⁄2 to 21⁄4 in. long, 1⁄12 in. or less wide, dark green, persisting three, four, or more years; leaf-sheath 3⁄16 in. long, persistent. Cones obliquely conical, up to 2 in. long, 3⁄4 in. wide at the base before expanding; scales terminated by a slender spine which wears away in time.

Native of the coast region of western N. America, from Alaska to S. California; discovered by Douglas in 1825; introduced shortly before 1855. It belongs to the group of two-leaved pines with persistent leaf-sheaths, and cylindrical, resinous winter-buds. In the absence of cones it might be confused with the mountain pine of Europe, P. uncinata, but in that species the leaves persist for five to ten years and the leaf-sheath is longer – up to 5⁄8 in. long.

In recent years P. contorta has become an important forestry tree in Britain, especially as a pioneer tree on poor peaty soils. Among the largest specimens in collections are: Grayswood Hill, Haslemere, Surrey, pl. 1886, 66 × 83⁄4 ft (1971); Warnham Court, Sussex, 73 × 91⁄4 ft (1971); Westonbirt, Glos., in Broad Drive, 61 × 9 ft (1970); Bodnant, Denb., pl. 1876, 105 × 93⁄4 ft (1974); Ashford Castle, Co. Mayo, Eire, 88 × 121⁄4 ft (1966).

P. contorta, in the wide sense, is a very variable species and there is no unanimity as to how it should be subdivided. The two varieties treated below are not clearly demarcated and are themselves variable. The complex is discussed by W. B. Critchfield in Geographic Variation in Pinus contorta (Maria Moors Cabot Foundation Publ. Vol. 3, 1–118 (1957)).

From the Supplement (Vol. V)

specimens: Grayswood Hill, Haslemere, Surrey, pl. 1876, this tree has been removed; Warnham Court, Sussex, 82 × 91⁄2 ft (1983); St Clere, Kent, 60 × 8 ft (1983); Bowood, Wilts., 79 × 8 ft and 77 × 81⁄4 ft (1984); Westonbirt, Glos., Broad Drive, 66 × 91⁄2 ft (1982); Bodnant, Gwyn., pl. 1876, this tree was blown down 1974; Castle Milk, Dumfr., 80 × 71⁄2 ft (1984).

var. latifolia – specimens: Dropmore, Bucks., 84 × 6 ft (1982); Leonardslee, Sussex, 92 × 51⁄2 ft (1984); Westonbirt, Glos., Pool. pl. 1875, 82 × 8 ft (1979); Bodnant, Gwyn., 67 × 61⁄2 ft (1981); Culcreuch Castle, Stirlings., 94 × 7 ft (1984).

† cv. ‘Frisian Gold’. – Young foliage becoming a striking gold, most intense during the winter. Low, spreading habit, at least when young. This arose as a mutation in the nursery of J. D. zu Jeddeloh, Germany, around 1962, and was named in 1979.