Rocky Mountain bristlecone pine (4). |
Pinus aristata
Engelmann 1862
Common NamesRocky mountain bristlecone pine (2), hickory pine (5), Colorado bristlecone pine (6).Taxonomic notesSyn: Pinus balfouriana Greville & Balfour var. aristata (Engelmann) Engelmann (6).Description"Trees to 15m; trunk to 1m diam., strongly tapering, twisted; crown rounded, flattened (sheared), or irregular. Bark gray to red-brown, shallowly fissured, with long, flat, irregular ridges. Branches contorted; twigs pale red-brown, aging gray, puberulent, young branches resembling long bottlebrushes because of persistent leaves. Buds ovoid-acuminate, pale red-brown, ca. 1 cm, resinous. Leaves 5 per fascicle, upcurved, persisting 10-17 years, (2-)3-4 cm x 0.8-1 mm, mostly connivent, deep blue-green, with drops and scales of resin, abaxial surface with strong, narrow median groove, adaxial surfaces conspicuously whitened by stomates, margins entire or distantly serrulate, apex conic-acute to conic-subulate; sheath 0.5-1.5 cm, scales soon recurving, shed early. Pollen cones ellipsoid, ca. 10 mm, bluish to red. Seed cones maturing in 2 years, shedding seeds and falling soon thereafter, spreading, symmetric, lance-cylindric before opening, lance-ovoid to ovoid or cylindric when open, 6-11 cm, purple to brown, nearly sessile; apophyses much thickened; umbo central, with triangular base, extended into slender, brittle prickle 4-10 mm. Seeds obliquely obovoid; body 5-6 mm, gray-brown to near black; wing ca. 10-13 mm. 2 n =24." (6).Needles of Pinus aristata are usually narrower and sharper than in P.longaeva and P.balfouriana , and the leaves almost always have a narrow, median groove on the abaxial surface (6). RangeUSA: Montane to subalpine areas of Colorado, New Mexico and Arizona (the San Francisco Peaks) at elevations of 2300 to 3650 meters (1, 6). See also (9).Big TreeDiameter 107 cm, height 23 m, crown spread 12 m. Locality: Carson National Forest, NM. Also: Diameter 112 cm, height 22 m, crown spread 10 m. Locality: Colfax County, NM (8).OldestA crossdated age of 2,435 years was determined for specimen CB-90-11, sampled by Brunstein and Yamaguchi in central Colorado (2, 7).DendrochronologyEthnobotanyObservationsAn ancient timberline grove can be seen along the Auto Road on Mt. Evans, Colorado. This grove has been somewhat vandalized by wood collectors. A more pristine stand can be found at timberline on the San Francisco Peaks of Arizona, although this requires a half-day walk to visit. The species also occurs as an early successional montane forest tree; in this role, it is plentiful in the western Pikes Peak area or Colorado, from the lower Peak west to the Woodland and Cripple Creek areas.RemarksWhite pine blister rust ( Cronartium ribicola ), an introduced fungal disease, has afflicted this and certain other white pines (5).
Citations(1) Silba 1986 .(2) Brunstein, F.C. and D.K. Yamaguchi. 1992. The oldest known Rocky Mountain bristlecone pines ( Pinus aristata Engelm.). Arctic and Alpine Research 24(3):253-256. (3) Elmore & Janish 1976 . (4) Elias 1987 . (5) Peattie 1950 (includes P. longaeva ). (6) Robert Kral at the Flora of North America online . (7) Brown 1996 . (8) American Forests 1996 . (9) Robert S. Thompson, Katherine H. Anderson and Patrick J. Bartlein. 1999. Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America. U.S. Geological Survey Professional Paper 1650 A&B. URL= http://greenwood.cr.usgs.gov/pub/ppapers/p1650-a/pages/conifers.html, accessed 22-Jan-2000. See also: Little 1980 (includes P. longaeva ), FEIS database . |
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