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
- Sun. Prefers well-drained, moist, deep site. Resistant to drought and tolerates
- The Sequoia pitch moth attacks ponderosa pine. Larvae of this insect bore into the tree's
cambium layer, especially around injuries and pruning cuts, and this stimulates pitch and resin flow.
Only prune in the months of October through January. In the Willamette Valley,
trunks may produce much pitch in response to insect attack. However,
genotypes adapted to Valley conditions are reportedly less prone to serious injury by pitch moths.
- 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.