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A tree 20 to 80 ft high in this country, occasionally up to 100 ft in the wild; young shoots glabrous, bright brown; buds cylindrical, 3⁄4 to 1 in. long, 1⁄8 to 1⁄4 in. wide, resinous. Leaves in threes, falling the third or fourth year, 4 to 71⁄2 in. long, slender, bright green, finely pointed, minutely toothed; leaf-sheath 1⁄3 to 1⁄2 in. long, persistent. Cones slenderly conical, usually 4 to 5 in. long, 2 in. wide at the oblique base, deflexed, with the scales near the base on the upper side developing the conical, spine-tipped knobs or prominences referred to in the popular name; the cones are produced in whorls of three or more, and persist on the branches for sometimes thirty or forty years, or until the death of the tree. At first they have a stalk 3⁄4 in. long, which gradually becomes enclosed in the thickening branch. Bot. Mag., t. 8717.
Native mainly of California, but extending north into Oregon, south into the Mexican state of Baja California; discovered and introduced in 1847 by Hartweg. It has no special merits as an ornamental tree, although on account of its long-persisting cones it is a very interesting one. On a piece of branch, 4 ft long, from a tree grown at Bayfordbury and now preserved at Kew, there are over forty cones. It is botanically allied to P. radiata, but differs in the larger, stiffer, grey-green leaves and narrower cones. It is also a hardier tree, and according to Jepson, inhabits the most desolate and inhospitable stations for tree growth in the Californian mountains. As may be judged from the life-history of its cones, it is admirably adapted to survive as a species on fire-swept zones. (See also P. muricata.)
A tree at Bodnant, Denb., pl. 1902, measures 80 × 101⁄2 ft (1974). Two trees at Borde Hill, Sussex, are of about the same age; they measure 75 × 61⁄2 ft (Pinetum) and 76 × 53⁄4 ft (Warren Wood) (1974).
specimens: Borde Hill, Warren Wood, 72 × 53⁄4 ft (1981) (the other tree mentioned is dead); Wakehurst Place, Sussex, 66 × 4 + 31⁄4 + 3 ft (1979); National Pinetum, Bedgebury, Kent, pl. 1926, 52 × 51⁄4 ft (1978); Bodnant, Gwyn., the tree mentioned was blown down c. 1980.
† P. attenuata × P. radiata – This hybrid is represented at the Forest Research Station, Alice Holt, Hampshire; and in the National Pinetum, Bedgebury.