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Jepson Interchange (more information)
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James R. Griffin

Tree or shrub, monoecious, evergreen
Stem: young crown conic; twig not grooved, resinous, generally persistent
Leaves simple, generally alternate, sometimes in bundles or appearing ± 2-ranked, linear or awl-like; bases decurrent, sometimes woody, persistent several years
Pollen cone generally < 6 cm, not woody, deciduous
Seed cone generally woody; bracts, scales generally persistent; scale not peltate, fused to or free from subtending bract
Seeds 2, on upper side of scale base
Genera in family: 10 genera, 193 species: mostly n hemisphere; many of great commercial value, supplying > half of world's timber
Reference: [Price 1989 J Arnold Arbor 70:247–305]



Stem: young crown conic, mature crown often rounded or flat; branches ± whorled in young plants; young bark smooth, mature bark furrowed; bud ± conic, generally resinous
Leaves generally 2.5–35 cm, generally sessile, in bundles of 1–5; bundles solitary in axils of alternate, awl-like bracts, each bundle enclosed at base in a sometimes deciduous sheath of bracts, generally persistent several seasons
Seed cones often whorled, generally maturing and opening 2nd season, sometimes persistent on stem; stalk 0 or < 16 cm; bract included, fused to scale, minute; scale tip reflexed and elongated 3–7 cm, or often with a rounded or angled, often prickled knob < 3 cm
Seed: coat hard, sometimes woody
Chromosomes: 2n=24 for all reports
Species in genus: 94 species: n hemisphere
Etymology: (Latin: pine)
Reference: [Millar & Critchfield 1988 Madroño 35:39–53]


P. ponderosa Laws.


Stem: trunk < 68 m, 2.2 m wide; branches sometimes lacking in lower half when mature; mature bark generally yellow-brown, furrows shallow, well spaced, forming plates, odor not banana-, pineapple-, or vanilla-like; mature crown short, conic or flat-topped; bud resinous, scales red-brown, dark-hairy
Leaves generally 3 per bundle, 12–26 cm, < 2 mm thick, not glaucous, deep green; sheath persistent
Seed cone ± spreading or recurved, generally 9–18 cm, ovoid, dark brown; stalk < 2 cm, persistent with basal scales; scales generally blackish on lower surfaces; knob prickles < 3 mm
Seed < wing
Ecology: Mixed-conifer, lower mixed-evergreen forests, generally absent from serpentine
Elevation: 150–2300 m.
Bioregional distribution: California Floristic Province (except North Coast, Great Central Valley, South Coast), East of Sierra Nevada
Distribution outside California: to British Columbia, Montana, Nebraska, n Mexico
Horticultural information: DRN, SUN: 1, 4, 5, 6, 15, 16, 17 &IRR: 2, 3, 7, 8, 9, 14, 18, 19.

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