Arizona Wild Flowers
Wildflower Pictures And Photos

Two Leaf Pinyon Pine, Pinus edulis

Two Leaf Pinyon Pine Pinus edulis, Pine Family: ( Pinaceae ), Two Leaf Pinyon Pine. Also called: . Pinyon Pines are perennia, evergreen trees that are monecious, with seed-bearing (female, "pistillate") and pollen bearing (male, "staminate") structures that are separate, but on each tree. Pinyons are a soft, dark green in color. Throughout their adult life Pinyons have a rounded symmetrical shape, but after many decades most Pinyons lose their lower branches. They grow 30 to 45 feet tall with trunks, up to three feet in diameter, with a handsome 30 foot crown spread. Pinyons live long lives, perhaps 800 years . Pinyon Pine nuts take about twenty-six months to mature: cone buds are formed in the first summer; then a small cone forms, opens, is pollinated, and closes in the second summer; this cone reopens in the third summer allowing the pollen inside to fertilize the eggs. Growth is then rapid and by the end of the third summer the green, sappy, two inch seed cone matures, dries to light brown, and opens. Light colored seed husks are almost always empty; good seed husks are usually dark brown. The buff-yellow pine nuts inside the good husks are a mainstay of many Colorado Plateau animals. Our photos were taken near Jacob's Lake, north of the Grand Canyon on the Kaibab Plateau of the Colorado Plateau. The Kaibab Plateau is an "island" of forested land surrounded by a sea of sage and grasslands. "Kaibab" is a Paiute Indian word that translates to "mountain lying down." Arizona has 3,666 species of native and naturalized plants in 1,003 genera and 145 families (Lehr and Pinkava, 1980). Flowers/Inflorescence: Cones. Unisexual, in clusters at the ends of branches. The male cones occurring in clusters of 20 to 40, dark red to purplish red to yellow. Female cones are solitary and purplish. Mature female cones appear as "pine cones", light brown to tan in color with thick scales. The cones don't mature until September of the second year. Stems: Twigs are smooth when young. Branches are rough and scaly. The bark is thin, gray to reddish-brown or nearly black. The trunk is frequently twisted and crooked. The bark is irregularly furrowed with small scales. Pine gum resin abundant. Ecological Adaptations: The woodland mosaic formed by pinyon pine occurs primarily on the high plains, plateaus, mesas, canyons, foothills, and lower mountain slopes of the Colorado Plateau. Sites are intermediate between ponderosa pine and submontane scrub above, and semiarid grassland or sagebrush steppe below. In the Great Basin, P. edulis is replaced by P. monophylla. Pinyon occurs most commonly at elevations between 4,500 and 7,500 feet where annual precipitation ranges from 12 to 18 inches. The distribution of pinyon pine is primarily a function of climate. Its lower limits are determined by lack of moisture; upper limits by biotic competition, low temperatures, and excessive soil moisture. Therefore, the elevational zones it occupies vary considerably depending on local topography and geographical location. Pinyon pine usually grows on the higher elevation sites in the pinyon-juniper woodlands it occupies. The seeds are important wildlife food for several songbirds, quails, squirrels, chipmunks, black bears, and mule deer. The seed crop of pinyon pine is valuable and is used in making candies, cakes, and cookies. In the past the seeds were a staple food in American Indian diets and were eaten raw, roasted, or ground into flour. Today, some incense is made from the crushed cones. Native American still use the pitch as a caulking compound for watertight baskets and as glue for turquoise jewelry. The annual harvest of pinyon nuts exceeds 1 million pounds. This crop is second in commercial value only to pecans among the uncultivated nuts of the United States. Singleleaf Pinyon Pine (P. monophylla) nuts are larger and more desirable than those from P. edulis. The tree is also desired as a Christmas tree because of its aromatic fragrance, and the wood is also used for fuel and fence posts. Height: 30 to 45 feet tall and three feet in diameter, with a 30 foot crown spread. Buds: Buds ovoid, to 2 cm, 1 cm broad, red-brown, very resinous; scale margins white-fringed. Bud Time: Mid March - May. Leaves: Needles about two inches long, in bundles of twos, thin, and dark green. New growth is bluish-green turning yellowish-green. Bark: Dark, tight, fissured bark. Cones: Yellowish papery male cones, female pinecones, 2 to 6 inches in length, conical to ovate, stalk nearly absent; cone scales thickened at the apex, with a small apical spine, and with a raised keel. Seeds: Pine nuts. Found: Semi-desert, foothills. Woodlands. Dry and rocky soils. Associated Species are: Utah juniper, big sagebrush, Indian ricegrass. Elevation: 4,500 to 7,500 Feet. Habitat: Widely distributed in western North America, most often occurring in extensive pure stands. Miscellaneous: Photos Taken Near Jacob's Lake Arizona, 3-6-2007.