About Pinus cembroides subsp. lagunae (Rob.-Pass.) D.K.Bailey
Pinus cembroides is a small to medium-sized tree that grows 8 to 20 metres (26 to 66 ft) tall, with a trunk that can reach up to 50 centimetres (20 in) in diameter. Its bark is dark brown, thick, and deeply fissured at the base of the trunk. Its leaves, called needles, grow in a mix of pairs and groups of three; they are slender, 3 cm (1+1⁄4 in) to 6 cm (2+1⁄4 in) long, dull yellowish green, and have stomata on both their inner and outer surfaces. The cones are round, measuring 3 cm (1+1⁄4 in) to 4 cm (1+1⁄2 in) long and wide when closed. They start out green, ripen to yellow-brown after 18–20 months, and have only a small number of thick scales, typically with 5 to 12 fertile scales. When mature, the cones open to 4 cm (1+1⁄2 in) to 5 cm (2 in) wide, and retain seeds on their scales after opening. The seeds are 10 mm (3⁄8 in) to 12 mm (1⁄2 in) long, with a thick shell, pink endosperm, and a vestigial 2 mm (1⁄16 in) wing. The native range of this tree extends from far western Texas in the United States, where it is only found in the Chisos and Davis Mountains, south through much of Mexico. It is widespread along the Sierra Madre Oriental and Sierra Madre Occidental ranges, and occurs less commonly in the eastern Eje Volcánico Transversal range. A disjunct population is located in the Sierra de la Laguna of southern Baja California Sur; some authorities classify this population as a separate species, P. lagunae, which is the subspecies Pinus cembroides subsp. lagunae. It grows at moderate altitudes, mostly from 1,600 to 2,400 m (5,200 to 7,900 ft), in areas with low annual rainfall between 380 to 640 mm (15 to 25 in). The related taxon Pinus orizabensis is found farther south in the Mexican state of Veracruz. In its ecological interactions, Mexican jays disperse the seeds of this tree by plucking seeds from open cones. The jays use the seeds as a major food source, store many seeds for later use, and some of these stored seeds are left unused and germinate into new trees. Abert's squirrels also feed on these seeds, preferring them over the seeds of ponderosa pine. In terms of human use, the seeds are widely collected across Mexico, where they are the main edible pine nut in the region. They are palatable when raw, but their flavor is considered improved by roasting.
