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A tree 40 to 50, occasionally 90 ft high, of curiously thin habit; young shoots blue-white, not downy, with the leaves clustered at the apex only, the major part naked except for the awl-shaped scale-leaves, 1⁄2 in. long. Leaves in threes, mostly falling the third year, 8 to 12 in. long, of a pale greyish green, with two narrow flat faces, and one rounded broad one, all lined closely with stomata, extremely minutely toothed at the margin, slenderly and sharply pointed; leaf-sheath 3⁄4 to 1 in. long, persistent. Cones produced on stout stalks about 2 in. long, ovoid, 6 to 10 in. long, 4 to 6 in. thick, often remaining on the branch long after the seeds have fallen; scales terminated by a large, triangular, hooked spine.
Native of California, whence it was introduced by Douglas in 1832. Most nearly allied to P. coulteri, and with similar large, heavy, spiny cones, it is very readily distinguished by its thin foliage, smoother and more slender young shoots, and narrow cylindrical winter-buds. The young shoots when cut have the same orange-like odour as in P. coulteri, P. ponderosa, and P. jeffreyi. The seeds are large like those of P. coulteri (but with much shorter wings), and were formerly much eaten by the Digger tribe of Indians. It is not a particularly ornamental tree, being thinly furnished with foliage, but is interesting in the curious contrast between the heavy trunk and the thin, light, shadeless head of branches. It is a light-demanding tree, growing in the wild on hot, dry slopes, where it forms open stands on its own or mixed with oak.
There is an example in the Pinetum of the Royal Horticultural Society at Wisley, measuring 62 × 5 ft (1968), and a slightly larger one at Wakehurst Place, Sussex.
specimens: R.H.S. Garden, Wisley, Surrey, this tree no longer exists; Wakehurst Place, Sussex, pl. 1913, 66 × 53⁄4 ft at 2 ft (1971); Dropmore, Bucks., pl. 1912, 76 × 51⁄4 ft (1982); National Botanic Garden, Glasnevin, Eire, 64 × 61⁄4 ft (1980).