Trees to 10m; trunk to 0.5m diam., straight, much branched; crown dense, becoming rounded. Bark redbrown, irregularly furrowed and cross-checked to irregularly rectangular, plates scaly. Branches spreading to ascending, persistent to trunk base; twigs slender, pale orangebrown, puberulent-glandular, aging brown to gray-brown. Buds ovoid, light-redbrown, ca. 0.4–0.5cm, slightly resinous. Leaves (3–) 4 (–5) per fascicle, persisting 3–4 years, (2–) 3–6cm × (1–) 1.2–1.7mm, curved, connivent, stiff, green to blue-green, margins entire to minutely scaly-denticulate, finely serrulate, apex subulate, adaxial surfaces mostly strongly whitened with stomatal bands, abaxial surface not so but 2 subepidermal resin bands evident; sheath 0.5–0.6cm, scales soon recurved, forming rosette, shed early. Pollen cones ovoid, ca. 10mm, yellowish. Seed-cones maturing in 2 years, shedding seeds and falling soon thereafter, spreading, symmetric, ovoid before opening, broadly ovoid to depressed-globose when open, (3–) 4–8 (–10) cm, pale yellowbrown, sessile to short-stalked, apophyses thickened, strongly raised, diamond-shaped, transversely keeled, umbo subcentral, low-pyramidal or sunken, blunt. Seeds obovoid, body ca. 15mm, brown, wingless.

Habitat: Dry rocky sites
Elevation: 1200–1800m

Distribution

• Generated Map
• Legacy Map

Calif., Mexico in Baja California

Discussion

Pinus quadrifolia is the rarest pinyon in the flora. It hybridizes naturally with P. monophylla.

Selected References

None.

Lower Taxa

None.

"relatively thin" is not a number.