General: Pine Family (Pinacaeae). Singleleaf pinyon is an evergreen tree reaching heights of up to 12 meters. When young, it forms a pyramidal or rounded silhouette against the sky, while mature pinyons display a more ungroomed, irregular branching appearance. The cylindrical, bluish-gray leaves are generally one per bundle and 1 to 2 in. in length. The female cones are wind-pollinated. The subglobose cones ripen in August of the second growing season, full of 1/2-inch long, wingless seeds. Pinyon trees produce cones every three to seven years. Trees usually do not start bearing cones before they are 35 years old and do not start producing good seed crops before 100 years.