Common Names
Washoe pine (2), 'North Plateau' Ponderosa pine.Taxonomic notes
Pinus washoensis is likely synonymous with the type subspecies of P. ponderosa (q.v.). However, its cones are fairly distinctive and I am not fully persuaded that the described P. washoensis populations do not warrant distinction as a variety or even a subspecies of P. ponderosa. Genetic analyses will probably be required before the ponderosa/washoensis problem is resolved in a satisfactory manner. This page is retained on the Database to provide information on what is at least a distinctive set of Ponderosa populations.Description
"Trees to 60 m; trunk to 100 cm diam., straight; crown pyramidal. Bark yellow-brown to reddish, fissured, plates scaly. Branches spreading-ascending; twigs stout, orangish, aging gray, rough. Buds ovoid, red-brown, 1.5-2 cm, not resinous; scale margins fringed. Leaves (2)3 per fascicle, spreading-ascending, persisting (2)4-6(7) years, 10-15 cm × ca. 1.5 mm, slightly twisted, gray-green, all surfaces with stomatal lines, margins finely serrulate, apex acuminate; sheath 1-2 cm, base persistent. Pollen cones cylindric, 10-20 mm, red-purple. Seed cones maturing in 2 years, shedding seeds soon thereafter, not persistent, spreading, slightly asymmetric, ovoid-conic before opening, broadly ovoid when open, 7-10 cm, tan or pale red-brown, sessile, abaxial surface of scales darker and sharply contrasting in color with adaxial surface; apophyses slightly raised, low pyramidal; umbo central, narrowly pyramidal, tapering into short, reflexed, fine prickle. Seeds ellipsoid; body ca. 0.8 cm, gray-brown; wing to 16 mm. 2n=24" (2).Range
USA: NW Nevada and adjacent California at 2100-2500m in dry montane forests (1, 2).Big Tree
Diameter 104 cm, height 27 m, crown spread 16 m, located in Thomas County, CA (3).Oldest
Dendrochronology
Ethnobotany
Observations
Remarks
Species is rare enough to be of conservation concern (2)."Pinus washoensis often occurs in large stands and resembles P. jeffreyi. The number and posture of seed-cone scales fall within the ranges given for P. jeffreyi. The abaxial surface of these scales has a significantly darker pigmentation, however; such a color contrast is not apparent in P. jeffreyi. Forest geneticists have developed hybrids between P. washoensis and related yellow pines, but no natural hybrids have been observed" (2).
Citations
(1) Silba 1986.(2) Kral in Flora of North America online.
(3) American Forests 1996.
See also:
Lanner 1983.
Little 1980.
FEIS database.
[Pinus] [Pinaceae] [home]
This page is from the Gymnosperm Database
URL: http://www.geocities.com/RainForest/Canopy/2285/pi/pin/washoensis.htm
Edited by Christopher J. Earle
E-mail:earlecj@earthlink.com
Last modified on 28-Jan-1999