Kingdom: Plantae

Phylum: Coniferophyta -- conifers

Class: Pinopsida

Order: Pinales

Family: Pinaceae -- pine family

Variety: Two phases are recognized, var. scopulorum and var. ponderosa. They tend to intergrade in our area.

Common Name: ponderosa pine, western yellow pine, blackjack pine, bull pine

Species Code: PIPO, PIPOP, PIPOS

Origin: Native to dry sites at low to moderate elevations, often extending into grasslands as individuals, forming pure stands of open forest with a herbaceous understory at the transition to forested areas, and extending into Douglas fir forest from southern British Columbia to Baja California and east to Texas and North Dakota.

Rare: no

Form: tree, coniferous, to 60 meters tall, trunk straight; bark thick, furrowed and dark reddish-brown, becoming darker, platy, and flaking with age; branches descending to spreading and ascending, often self-pruning on the lower trunk of older trees; twigs thick, rough; buds ovoid, resinous, reddish-brown.

Duration: perennial

Longevity: long-lived

Habitat Type: riparian areas, dry forest, occasionally extending into Palouse grassland as individuals.

Wetland Indicator Status: FACU-

Leaves: needles borne in clusters near the end of branches, mostly in groups of 3, but sometimes in 2’s and occasionally even 4’s or 5’s, 12-25 cm long, yellowish green, generally persisting 4-6 years.

Mature height: to 200 feet

Flowers: The conifers are gymnosperms and do not have flowers in the traditional sense.

Anthesis: May - June

Anthesis starts on: Late May

Anthesis ends on: Early June

Fruit: staminate cones clustered, yellow to purple, 20-30 cm long, cylindric; pistillate cones reddish-purple when young, turning brown, maturing late in the second summer, ovoid, 8-14 cm long, often in clusters, subsessile, horizontal; scales with a thickened prickly tip; seeds brown, 6-7 mm long, wing 15-25 mm long; cotyledons 6-12.

Characteristics:
P. ponderosa seedlings are shade intolerant.
On the Palouse, stands are usually widely spaced and open with a considerable variety of other species in the understory.
Reproduces sexually by seed.
12,000 seeds/lb (USDA NRCS PLANTS Database 2010).
Average 12,000 seeds/lb with a range of 7,000 to 23,000 (Krugman & Jenkinson undated).
Taprooted.
2n=24 (Hitchcock et al 1969, Baldwin et al 2004)
Wind pollinated.
Plants are monoecious.
The cambium layer from young trees is edible, as are the seeds. The wood has many uses.
Seeds are windborne for short distances. They are also dispersed by animals.
Ponderosa pine forests provide shelter and habitat for wildlife. Small birds and mammals eat the seeds.
Rocky Mountain elk make minor use of the plants in winter (Kufeld 1973).
Browsed by deer and mountain sheep. Causes cattle to abort (Stubbendieck et al 1997).
P. ponderosa is a host for the larva of the western pine elfin (Incisalia eryphon) butterfly (Pocewicz 2005).

Comments:
The conifers are gymnosperms and do not have flowers in the traditional sense. Instead, the male and female reproductive parts are borne in separate strobili (cones) on the same tree. The male cones drop from the tree soon after the pollen is released.

Sun requirement: full sun to partial shade

Soil moisture: mesic

Precipitation: 15-25 inches (USDA NRCS PLANTS Database 2010).

Fire: Mature trees are highly resistant to low intensity fires due to the thick, corky bark and the tendency to self-prune the lower limbs. They are killed if fire moves into the canopy, however.

Sowing time: fall

Transplant time: spring

Stratification: cold moist

Seed yield: high

Seed harvest: difficult

Seed cleaning: difficult

Planting duration: long

Seed shatter: medium

Seed size: large

Seed harvest date: August, September

Herbaria: Specimen data and digital resources from The Consortium of Pacific Northwest Herbaria

Keywords: native perennial upland tree

Propagation:
Search the Native Plant Network for propagation protocols

Other Propagation Information:
30-60 days cold moist stratification at 0.5 to 5^oC (Krugman & Jenkinson undated).
P. ponderosa seedlings are shade intolerant.
Reproduces sexually by seed.

Notes: A good landscape tree for warm, dry sites (Idaho Native Plant Society 1999).

References:
Baldwin, B.G., S. Boyd, B.J. Ertter, D.J. Keil, R.W. Patterson, T.J. Rosatti, and D.H. Wilken (eds). 2004. Jepson Online Interchange for California Floristics. University and Jepson Herbaria, University of California, Berkeley, CA. Accessed 1/1/10 online at http://ucjeps.berkeley.edu/interchange.html

Hitchcock, C. Leo, Arthur Cronquist, Marion Ownbey, and J.W. Thompson. 1969. Vascular Plants of the Pacific Northwest. University of Washington Press. Seattle, WA. 5 vol.

Idaho Native Plant Society. 1999. Native Plants of Northern Idaho for Landscaping and Restoration. INPS White Pine Chapter. Moscow, ID. Online at http://www.idahonativeplants.org/guides/NorthIdahoGuide.aspx

Krugman, Stanley L. and James L. Jenkinson. undated. Pinus L. pine. In: Bonner, Franklin T., and Rebecca G. Nisley (eds.). Woody Plant Seed Manual. USDA Forest Service. Available online at http://www.nsl.fs.fed.us/wpsm/

Kufeld, Roland. 1973. Foods Eaten by the Rocky Mountain Elk. Journal of Range Management 26:106-113.

Pocewicz, Amy. 2005. Host Plants of Palouse Butterfly Species. 2 page handout to accompany the April 2005 presentation to the Palouse Prairie Foundation.

Stubbendieck, James, Stephan L. Hatch, and Charles H. Butterfield. 1997. North American Range Plants. 5th edition. University of Nebraska Press, Lincoln, NE. 501 pp.

USDA NRCS. 2010. The PLANTS Database (http://plants.usda.gov, 2 January 2010). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Links:
Plant Profile from the USDA PLANTS Database
Species account for var. ponderosa from the Fire Effects Information System
Species account for var. scopulorum from the Fire Effects Information System
Species description from Flora of North America
Species information from the University of Washington Herbarium
Plant Guide from the USDA PLANTS Database