Knobcone Pine, Pinus attenuata

Knobcone pine (Pinus attenuata) grows in the mountains of southern Oregon to Baja California. This tree is usually found in pure stands but can mix in with the Bishop pine and the Monterey pine along the Oregon-California coastline. This tree grows in shallow rocky infertile soil. The knobcone pine is a relatively short lived tree living 75-100 years.

The Knobcone pine grows at sea level up to 5500 feet in elevation and is a short to medium tree growing to heights of 26-79 feet with a trunk diameter from 13.5-23 inches, often shrub like in poor soil conditions. The trunk is straight with a crown that is cone shaped. The bark is gray-brown when immature turning dark-dray-red-brown when mature. The bark is smooth and flaky when young turning into shallow scaly ridges as it ages. The needles are yellow-green, grow in bundles of three, usually twisted, and measure 3.5-6 inches long. Female cones grow in groups of four or five and measure 3.15-6.29 inches long.

The cones remain closed until exposed to fire, at which time the tree dies and the cones open to release the seeds. These tree will cease to exist if there are no forest fires as the tree is dependent on the minerals in the soil released when it is burned.

Image Caption: Knobcone pine cone (Pinus attenuata). Credit: w:User:Geographer/Wikipedia (CC BY-SA 2.5)