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Shrub or tree to 8–12 m, trunk short, 0.5–0.6 m dbh. Bark thin, dark grey, with vertical scaly fissures on the lower trunk, the fissures orange-yellow. Crown dense and shrubby. Branchlets rough, pale greyish buff; vegetative buds 1–2 cm, pale grey-brown, slightly resinous. Leaves in fascicles of three (to four) (occasionally five, exceptionally two), persisting for three to four years, slightly curved, rigid, dark green on outer face with few stomata, glaucous blue-white stomatal bands on inner faces, triangular in cross-section, 4–6 × 0.07–0.11 cm, apex acute. Fascicle sheaths to 0.6–0.8 cm long, light grey-brown. Cataphylls 0.5–0.7 cm long, orange-brown. Female cones subterminal, solitary or in whorls of two to three; peduncles short, nearly sessile, with semi-persistent cataphylls. Cones 4.5–7.5 × 5–7.5 cm, dark green, maturing dark brown, mature in about 16 months; mature cones globose or subglobose with a flat base, forming an irregular rosette when fully open. Scales 30–35(–50) (of which 10–20 fertile), opening widely, weakly attached to cone rachis; apophysis thin, slightly raised with a transverse ridge, light brown to dark to reddish brown, smooth; umbo dorsal, 4–6 mm wide, slightly raised, dark brown to grey with a minute, deciduous prickle. Fertile seeds dark golden-brown (infertile seeds pale buff), 1.4–1.8 × 0.8–0.9 cm; wings vestigial, remaining attached to the seed scale. Perry 1991, Farjon & Styles 1997, Farjon et al. 1997, Farjon 2005a. Distribution MEXICO: Puebla, Tlaxcala, western Veracruz (in the high basin to the west of the mountains of Pico de Orizaba and Cofre de Perote). Habitat This species occurs in an area of scattered volcanoes, between 2100 and 2800 m asl. It mixes with P. cembroides in some areas. USDA Hardiness Zone 8. Conservation status Lower Risk. Illustration Farjon & Styles 1997.
This species is in some respects intermediate between Pinus cembroides and P. johannis. The leaves have stomata on both outer and inner faces as in P. cembroides, but with only a few on the outer face and densely on the inner faces, giving it the same bicoloured aspect as P. johannis. The cones and seeds, however, are larger than in either of these other two. It was named after detective work elucidated the identity of a tree growing at Kew that had been mislabelled P. nelsonii, by comparing it with herbarium material and wild trees in Orizaba, Mexico (Bailey 1983, Bailey & Hawksworth 1992), although its true relationship to other members of the P. cembroides complex is still debated (Gymnosperm Database 2007e). The Kew tree was received from H. Clinton Baker in 1910, and is rather attractive, with an appearance strongly suggestive of dry hillsides. It is currently a shapely 10 m tall, with a somewhat glaucous appearance from stiffly erect, bristly needles. Other than a few seedlings from it at Wakehurst