Kirsten Aamodt, Native Plants Class 2003
Common names: Bristlecone pine, foxtail pine, hickory pine.
Synonymy: Pinus balfouriana Greville & Balfour var.
aristata (Engelmann) Engelmann
Etymology: Pinus is Latin for pine. The specific epithet
can be translated into awned, probably referring to the incurved prickles
extending from the tips of the cone scales. (1).
Growth form: Pinus aristata is a tree achieving heights
of 15 m. The appearance is very bushy with a rounded crown, and dense
with foliage often stemming from ground level. Notable are the disfigured,
twisted, and sheared semblances these pines can acquire while demonstrating
their ability to continue to slowly grow in spite of the soil erosion;
drought; wind, sand and ice blasting occurring in their timberline habitats
(3, 4, 8).
Roots: In saplings the roots are sparse and successful
transplants become increasingly less successful with age and increased
Stem: Commonly malformed and up to a meter in diameter. Young
trunks will have smooth, pale gray and thin bark. On mature trees it
is reddish brown, scaly, shallowly furrowed, with flattened irregular
ridges. The wood is densely resinous. Branches can be contorted and
sheared to the leeward side with pale red-brown bark ageing to gray.
Twigs are stout, covered with soft hairs, orange turning black, clothed
in thick tufts of foliage resembling bottlebrushes. (4, 6, 8)
Leaves: Crowded together, the long persistent needles (10 -17
years (4, 6) are stout, upcurved, and 2.5-4 cm long by .08-1 mm wide.
Occurring in fascicles of 5, needles are deep blue-green, lustrous,
with drops or scales of white resin dotting their inside surface. There
is an obvious, narrow, median groove along the outside surface (4, 6,
Fruit: Pollen Cones: The male cones are ellipsoid, 10 mm long
and bluish to dark orange-red (4, 6, 8).
Seed Cones: The purple to brown seed cones are nearly sessile, 6-11
cm in length, mature in 2 years, and shed their seeds before falling.
The cone scales have a thickened triangular base extending into a fragile
incurved bristle 4-10 mm long. Seeds are 5-6 mm with a 10-13 mm long
grayish to black wing (3, 4, 5, 6).
Similar species: Populations of Pinus longaeva have
been separated from Pinus aristata by the Colorado Green River
drainage, a distance of 260 km, for millions of years. They differ from
each other in needle structure and cone morphology (5). Both are known
as Bristlecone pines, live in high alpine environments and are famous
for their longevity. Methuselah is the name given to a specimen of P.
longaeva that is considered the oldest living tree in the world.
Ages given vary from 4000 to 5000 years. Ages given for specimens of
P. aristata vary from 1500 to 2500 years. The two are definitively
distinguished by distribution. In Arizona, P. aristata grows
in conjunction with Pinus flexilis, which also has needles
in bundles of 5. However, the foliage of P. flexilis is bunched
at branch ends rather than clothing the entire branch and the cones
are larger, and lack the bristle (5, 8).
Life history: Perennial. Evergreen. Tree.
Native/introduced: Native, occurring in pure, same aged stands
or in associations with Pinus flexilis, Abies concolor,
Abies lasiocarpa, Picea engelmannii, Pinus ponderosa,
and/or Populus tremuloides in montane and subalpine areas at
elevations of 2300-3650 m (3, 8).
Photosynthetic pathway: C3
Phenology: Undaunted by the short growing season and daily temperature
extremes, P. aristata buds in June, shoots grow in July, and
active growth can occur from June to September. Pollen cones bud in
July and pollen falls in late July. Seed cones mature in July and open
in late September shedding seeds through October. Leaves are shed in
Distribution: CO, NM, and AZ (2, 5, 8). Also in CA,
NV and on the eastern slopes of the Laramie Range in southwest WY, south
through the San Juan Mountains of CO, to the Sangre de Cristo Mountains
of NM, with a disjunctive population occurring in northern AZ's San
Francisco Peaks in Coconino County (3, 9).
The soft, resinous wood has little lumber value, is locally used as
fuel or props in mines, salvage protected in Arizona (3, 4). Cover is
provided and seeds are edible by Clark's Nutcracker, various other small
birds and small mammals. Popular as a Bonsai specimen. Due to its longevity,
its greatest significance to modern man is as a cross reference for
radiocarbon dating and the tree ring chronologies for paleoclimatic
indicators, especially for temperature fluctuations. Fires are not problematic
in bristlecone habitats as severe weather factors inhibit understory
growth, and with needles shedding only every 10 -17 years, little litter
exists as fuel (3). Shoshoni Indians used a poultice of heated pitch
to apply to sores and boils (10).
1. Gledhill, David. 2002. The names of Plants 3rd Edition. Cambridge
2. USDA, NRCS. 2002 The PLANTS Database, Version 3.5 (http://plants.usda.gov/factsheet/doc/fs_abco.doc)
National Plant Data Center, Baton Rouge, LA. 70874-4490 USA
3. Ahlenslager, Kathy, 1986 (Nov.). U.S. Department of Agriculture,
Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory
(2003, October). Fire Effects Information System, [Online]. Available:
[Nov. & Dec. 2003].
4. Preston, Richard J., 1961. North American Trees. The M.I.T. Press.
5. Elmore, Francis H., 1976. Shrubs and Trees of the Southwest Uplands.
Southwest Parks and Monuments Association.
6. Morin, Nancy R., convening editor. 1993. Flora of North America Volume
2, Pteridophytes and Gymnosperm. N.Y. Oxford University Press.
7. Epple. Anne Orth. 1995. A Field Guide to the Plants of Arizona. The
Globe Pequot Press.
8. Department of Botany. Rheinische Friedrich-Wilhelms-University Bonn,
9. Kearney, Thomas H., Peebles, Robert H., 1961. Arizona Flora 2nd Edition.
University of California Press.
10. Moerman, Dan. University of Michigan. Native American Ethnobotany.
[Nov. & Dec. 2003].