Pinus ponderosa Pinaceae
Ponderosa Pine, Western Yellow Pine PI-nus pon-der-O-sa
- Conifer, evergreen tree, 60-100 ft (18-30 m), narrow, pyramidal when young, to an irregularly cylindrical, narrow crown. Bark brown-black in young trees, but in older trees yellowish brown or cinnamon and in large, flat, scaly plates. Needles long (13-25 cm) and in 3's or sometimes in 2's, crowded on branchlets, sharp at apex, horny point, stomatal lines on each surface. Cones 5-15cm long, conical or egg-shaped, almost stalkless, light, reddish-brown to gray-brown, armed with straight prickles.
- Sun. Prefers well-drained, moist, deep site. Resistant to drought and tolerates alkaline soil. The pitch moth, whose larvae bore into the cambium, especially around injuries, stimulate pitch flow. In the Willamette Valley, trunks may produce much pitch in response to insect attack. However, genotypes adapted to Valley conditions are less prone to serious injury by insects.
- Hardy to USDA Zone 3 British Columbia to Mexico, east to South Dakota and Texas. In the Pacific Northwest it is most commonly found east of the Cascades, however in Oregon it is common in the western valleys of the Willamette, Umpqua, and Rogue Rivers.
- Often confused with Pinus jeffreyi, several characteristics given to distinguish between the two species.
- Several subspecies and a few cultivated selections.
- ponderosa: heavy, the wood.
- Oregon State Univ. campus: behind Ag. and Life Sciences, much pitch on the trunk.