Trees to 60m; trunk to 1m 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--2cm, not resinous; scale margins fringed. Leaves (2--)3 per fascicle, spreading-ascending, persisting (2--)4--6(--7) years, 10--15cm ´ ca. 1.5mm, slightly twisted, gray-green, all surfaces with stomatal lines, margins finely serrulate, apex acuminate; sheath 1--2cm, base persistent. Pollen cones cylindric, 10--20mm, 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--10cm, 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. 0.8cm, gray-brown; wing to 16mm. 2 n =24.
Dry montane forests; of conservation concern; 2100--2500m; Calif., Nev.
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. Some workers regard P . washoensis as closely related to---or even conspecific with--- P . ponderosa .
