by Hillary Sellmeyer,
Native Plants Class
Common names: Western yellow pine, yellow pine, bull pine, blackjack
pine, pinabete (3).
Family: Pinaceae.
Synonymy: Pinus ponderosa P.& C. Lawson ssp. scopulorum
(Engelm.) E. Murr. (5).
Etymology: Pinus is derived from the Greek work "pitys."
Ponderosa refers to the heaviness of the tree trunk(1).
Identification
Growth form: Western yellow pine is a tall, erect tree.
Roots: The root system of Western yellow pine consists of a long
taproot (5 feet) and longer lateral roots (up to 10 feet). Lateral roots
may surface and grow up to 1 meter above ground in pine trees with Taxodium
distichum. These roots are hollow and provide aeration for the tree (6).
Stem: The trunk of the Western yellow pine can be up to 4 feet
in diameter. Braches arise from the yellow-brown trunk, and are short,
but strong. Branches are often bowed. Older shoots are glabrous and have
many ducts which exude the odor of the resin within them.. On older trees,
the trunk is protected by a cinnamon-red, deeply furrowed bark. This bark
may be up to 10 cm thick. The Western yellow pine can reach heights of
125 feet (4,6).
Leaves: Western yellow pine needles are dark green. Three needles
are bunched together in each fascicle. Needles are long and thin (7 inches
long, 1.8 mm wide), and persist on the tree for three years. Needles arise
out of the end of the shoot, and are covered by leaf sheaths
Female Cones : Persistent, light brown and oblong. They exist individually
on the tree, or in groups of five or less. They vary in length from 5-15
cm and are 3.5-5 cm wide. Cone scales have prickles that point outward.
The ripe seeds are brown and winged. Each seed is 7-10 mm long, while
each wing is 2.5-3 cm. (3,7).
Similar species: Pinus arizonica Engelm. (Arizona pine)
is a relative of Pinus ponderosa P.& C. Lawson var. scopulorum
Engelm. It is also native to the United States. Pinus arizonica
Engelm. is easily recognized by shorter cones and bundles of five needles
(vs. 3 per fascicle for Pinus ponderosa P.& C. Lawson var.
scopulorum Engelm.) (5).
Ecology
Life history: Western yellow pine is a long-lived (<600 years)
perennial (6).
Native/introduced: Native.
Photosynthetic pathway:
Phenology: Western yellow pine blooms from April to June. The cones
ripen between August and October. During this time, the seeds are dispersed
by wind (4).
Distribution: Idaho, east to North Dakota, south to Arizona and
east to Texas. This region also extends into southern Canada and northern
Mexico. Western yellow pine grows within the boundaries of the Rocky Mountains.
It is most commonly found on dry mountainsides and mesas. In Arizona,
Western yellow pine is found in Coconino, Navajo, Apache, Mojave, and
Yavapai counties in ponderosa pine and mixed conifer forest. Elevations
range.from 3500-9500 ft. (5).
Uses
Wildlife: The seeds of Western yellow pine are good forage for
small rodents and birds (2).
Ethnobotany: The Hopi used Western yellow pine for the roof beams
and ladders of their kivas. To promote rain, the Hopi smoked a mixture
of young needles and tobacco. Needles attached to prayer sticks are thought
to bring cold weather (8).
References
1. Athenic Systems. Tree Guide, Inc. http://www.athenic.com/index.htm.
(5 Dec. 2002).
2. Elmore FH. Shrubs and Trees of the Southwest Uplands. Tucson: Southwest Parks and Monuments Association; 1987. 110 p.
3. Epple AO. A Field
Guide to the Plants of Arizona. Guilford: The Globe Pequot Press;
1995. 14-15 p.
4. Stuart JD, Sawyer JO. Trees and Shrubs of California. Los Angeles: University of California Press; 2001. 85-87 p.
5. USDA, NRCS. 2002. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
6. Vandyke-Leake D, Leake JB, Leake-Roeder M. Desert and Mountain Plants of the Southwest. Norman: University of Oklahoma Press; 1993. 14 p.
7. Vidakovik M. Conifers: Morphology and Variation. Croatia: Grafickizavod Hrvatske;1991: 541-543 p.
8. Whiting AF. Ethnobotany
of the Hopi. Flagstaff: Northland Press; 1966: 40, 63 p.
