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Tree to 25 m, trunk erect, straight, 0.7–0.9 m dbh. Bark reddish brown; in older trees dark brown, breaking into long, irregular plates divided by wide, shallow fissures. Crown broad, open and rounded; trunk clear of branches for half to a quarter of its height. Branchlets stout, very rough; vegetative buds not resinous. Leaves in fascicles of (two to) three (to four, rarely five), persisting for two to three years, pale or yellowish green, straight or slightly curved, triangular in cross-section, (18–)20–35(–43) × 0.15–0.2 cm, apex acute. Fascicle sheaths 1.5–4 cm long, reddish brown, persistent. Cataphylls conspicuous, 1.5–2 cm long, recurved, dark brown or black. Male strobili cylindrical to ovoid-oblong. Female cones subterminal, single, paired or in whorls of three to five, peduncles stout and curved, initially persistent though eventually deciduous. Cones 8–15 × 6–10 cm, light brown and glaucous, mature in about 18–20 months; mature cones appear sessile, ovoid-oblong, curved, usually resinous. Scales 100–140, parting to release seeds, thick, woody, oblong; apophysis variably raised, rhombic to pentagonal, yellowish brown to light brown; umbo dorsal, with a 0.3 cm long, persistent, curved spine. Seeds light brown to grey with dark spots; wings effective, 1.8–2.5 × 0.7–1 cm, translucent yellowish brown; seedlings have a ‘grass stage’ of development. Farjon & Styles 1997, Farjon et al. 1997, Farjon 2005a. Distribution MEXICO: Chihuahua, Durango, Sinaloa, Sonora, Zacatecas; USA: southeast Arizona, extreme southwest New Mexico. Habitat Mountain slopes and plateaus between 1200 and 3000 m asl. USDA Hardiness Zone (7?–)8. Conservation status Lower Risk. Illustration Farjon & Styles 1997, Farjon 2005a; NT601, NT602. Cross-reference K217.
Pinus engelmannii is an interesting species, very well adapted to survive fires, much as P. palustris is, although the two occur in very different habitats; in appearance it is much more like P. ponderosa, though obviously differing in the long leaves. Pinus engelmannii has a ‘grass stage’ in its youth, and then thick, fire-resistant bark from an early age as it develops a more normal shape. The tree has a massive appearance at all stages, with thick stems and branches bearing impressive tufts of long leaves at their tip, making it well worth planting as a specimen tree. An individual at Kew of about 8 m, with slightly gaunt and twisted branches, that originated as seed collected in Durango in 1961 by David Hunt, looks as if it has been transplanted from a Wild West film set. The name Apache Pine also conjures up images of its habitat in the Mexico and US borderland mountains. It was among the pines introduced to the Forestry Commission in 1962 (Mitchell 1972), and from this and later introductions is well established in British and European gardens, apparently being quite hardy. The best specimen in the United Kingdom is at the Hillier Gardens, on the West Scree Lawn near Jermyn’s House, measured at 16 m (45 cm dbh) in 2006 and forming a fine trunk with a good crown, but this is much larger and older than any grown from the 1962 introduction, and must therefore predate it (M. Frankis, pers. comm. 2007). A selection is commercially available in the United Kingdom, under the presumably illegitimate name ‘Glauca’.