|Single-leaf Pinyon (Pinus monophylla subsp. monophylla)|
The pinyon (or piñon) pine group grows in the southwestern United States and in Mexico. The trees yield edible pinyon nuts, which were a staple of the Native Americans, and are still widely eaten. The wood, especially when burned, has a distinctive fragrance. The pinyon pine trees are also known to influence the soil in which they grow.
Some of the species are known to hybridise, the most notable ones being P. quadrifolia with P. monophylla, and P. edulis with P. monophylla.
The Pinyon Jay (Gymnorhinus cyanocephalus) takes its name from the tree, and pinyon nuts form an important part of its diet. It is very important for regeneration of pinyon woods, as it stores large numbers of the seeds in the ground for later use, and excess seeds not used are in an ideal position to grow into new trees. The Mexican Jay is also important for the dispersal of some pinyon species, as, less often, is the Clark's Nutcracker. Many other species of animal also eat pinyon nuts, without dispersing them.
The pinyon pine is very common in the Grand Canyon
- Pinus cembroides – Mexican Pinyon
- Pinus orizabensis – Orizaba Pinyon
- Pinus johannis – Johann's Pinyon or Border Pinyon (includes P. discolor)
- Pinus culminicola – Potosi Pinyon
- Pinus remota – Texas Pinyon or Papershell Pinyon
- Pinus edulis – Colorado Pinyon or Two-needle Pinyon
- Pinus monophylla – Single-leaf Pinyon
- Pinus quadrifolia – Parry Pinyon (includes P. juarezensis).
These additional Mexican species are also related and mostly called pinyons:
- Pinus rzedowskii – Rzedowski's Pine
- Pinus pinceana – Weeping Pinyon
- Pinus maximartinezii – Big-cone Pinyon
- Pinus nelsonii – Nelson's Pinyon
- Barth, R.C. (January 1980). "Influence of Pinyon Pine Trees on Soil Chemical and Physical Properties". Soil Science Society of America Journal 44 (1): 112–114. Retrieved 6 August 2012.
- WHITHAM, THOMAS G.; SUSAN MOPPER (1985-05-31). "Chronic Herbivory: Impacts on Architecture and Sex Expression of Pinyon Pine". Science 228 (4703): 1089–1091. doi:10.1126/science.228.4703.1089. Retrieved 6 August 2012.
- Mopper, Susan; Jeffry B. Mitton, Thomas G. Whitham, Neil S. Cobb and Kerry M. Christensen (June 1991). "Genetic Differentiation and Heterozygosity in Pinyon Pine Associated with Resistance to Herbivory and Environmental Stress". Evolution 45 (4): 989–999. Retrieved 6 August 2012.
- Bentancourt, Julio L.; William S. Schuster, Jeffry B. Mitton and R. Scott Anderson (October 1991). "Fossil and Genetic History of a Pinyon Pine (Pinus Edulis) Isolate". Ecology 72 (5): 1685–1697. Retrieved 6 August 2012.