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knobcone pine

bull pine, pin à bois lourd, pinabete, pino real, ponderosa pine, western yellow pine, yellow pine

Habit Shrubs or trees to 24m; trunk to 0.8m diam., usually straight; crown mostly narrowly to broadly conic. Trees to 72m; trunk to 2.5m diam., straight; crown broadly conic to rounded.
Bark

purple-brown to dark brown, shallowly and narrowly fissured, with irregular, flat, loose-scaly plates, on upper sections of trunk nearly smooth.

yellow- to red-brown, deeply irregularly furrowed, cross-checked into broadly rectangular, scaly plates.

Branches

ascending;

twigs slender, red-brown.

descending to spreading-ascending;

twigs stout (to 2cm thick), orange-brown, aging darker orange-brown, rough.

Buds

ovoid to ovoid-cylindric, dark red-brown, aging darker, ca. 1.5cm, resinous;

scale margins fringed, apex attenuate.

ovoid, to 2cm, fully 1cm broad, red-brown, very resinous;

scale margins white-fringed.

Leaves

3 per fascicle, spreading or ascending, persisting 4–5 years, (8–)9–15(–20)cm × (1–)1.3–1.8mm, straight or slightly curved, twisted, yellow-green, all surfaces with fine stomatal lines, margins serrulate, apex abruptly conic-subulate;

sheath (1–)1.5–2cm, base persistent.

2–5 per fascicle, spreading to erect, persisting (2–)4–6(–7) years, 7–25(–30)cm × (1–)1.2–2mm, slightly twisted, tufted at twig tips, pliant, deep yellow-green, all surfaces with evident stomatal lines, margins serrulate, apex abruptly to narrowly acute or acuminate;

sheath 1.5–3cm, base persistent.

Pollen cones

ellipsoid-cylindric, 10–15mm, orange-brown.

ellipsoid-cylindric, 1.5–3.5cm, yellow or red.

Seed(s)

cones maturing in 2 years, serotinous, long-persistent, remaining closed for 20 years or more, or opening on burning, in whorls, hard and heavy, very asymmetric, lanceoloid before opening, ovoid-cylindric when open, 8–15cm, yellow- or pale red-brown, stalks to 1cm;

apophyses toward outside base increasingly elongate, mammillate or raised-angled-conic, downcurved near base, scarcely raised on branchlet side, rhombic;

umbo central, low-pyramidal, sharp, upcurved.

cones maturing in 2 years, shedding seeds soon thereafter, leaving rosettes of scales on branchlets, solitary or rarely in pairs, spreading to reflexed, symmetric to slightly asymmetric, conic-ovoid before opening, broadly ovoid when open, 5–15cm, mostly reddish brown, sessile to nearly sessile, scales in steep spirals (as compared to Pinus jeffreyi) of 5–7 per row as viewed from side, those of cones just prior to and after cone fall spreading and reflexed, thus well separate from adjacent scales;

apophyses dull to lustrous, thickened and variously raised and transversely keeled;

umbo central, usually pyramidal to truncated, rarely depressed, merely acute, or with a very short apiculus, or with a stout-based spur or prickle.

2n

=24.

Pinus attenuata

Pinus ponderosa

Habitat Fire successional on dry slopes and foothills of Sierra Nevada and the Cascade and Coast ranges
Elevation 300–1200m (1000–3900ft)
Distribution
from FNA
CA; OR; Mexico in Baja California
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; CO; ID; MT; ND; NE; NM; NV; OK; OR; SD; TX; UT; WA; WY; BC; Mexico
[WildflowerSearch map]
[BONAP county map]
Discussion

Pinus attenuata, mostly a chaparral species, bears cones at an early age. Its seed crops are heavy, and a hot fire permits the seeds to be released. It forms hybrids with P. muricata and P. radiata.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Pinus ponderosa is the most economically important western yellow pine. Its wood is more similar in character to the white pines, and it is often referred to as white pine. The taxonomy of this complex is far from resolved.

Ponderosa pine (Pinus ponderosa) is the state tree of Montana.

Varieties 3 (3 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Leaves mainly 2-3 per fascicle, (7-)10-17 cm.
var. scopulorum
1. Leaves mainly 3-5 per fascicle, (7-)12-25(-30) cm.
→ 2
2. Buds very resinous; leaves commonly 3 per fascicle, 12-25(-30) cm × (1.2-)1.5-2 mm; pollen cones mostly red; seed cones 8-15 cm; twigs commonly not glaucous.
var. ponderosa
2. Buds slightly resinous; leaves commonly 4-5 per fascicle, 7-17 cm × 1-1.2(-1.5) mm; pollen cones mostly yellow; seed cones 5-8 cm; twigs usually glaucous.
var. arizonica
Source FNA vol. 2. FNA vol. 2.
Parent taxa Pinaceae > Pinus Pinaceae > Pinus
Sibling taxa
P. albicaulis, P. aristata, P. balfouriana, P. banksiana, P. cembroides, P. clausa, P. contorta, P. coulteri, P. echinata, P. edulis, P. elliottii, P. engelmannii, P. flexilis, P. glabra, P. jeffreyi, P. lambertiana, P. leiophylla, P. longaeva, P. monophylla, P. monticola, P. muricata, P. palustris, P. ponderosa, P. pungens, P. quadrifolia, P. radiata, P. resinosa, P. rigida, P. sabiniana, P. serotina, P. strobiformis, P. strobus, P. sylvestris, P. taeda, P. torreyana, P. virginiana, P. washoensis
P. albicaulis, P. aristata, P. attenuata, P. balfouriana, P. banksiana, P. cembroides, P. clausa, P. contorta, P. coulteri, P. echinata, P. edulis, P. elliottii, P. engelmannii, P. flexilis, P. glabra, P. jeffreyi, P. lambertiana, P. leiophylla, P. longaeva, P. monophylla, P. monticola, P. muricata, P. palustris, P. pungens, P. quadrifolia, P. radiata, P. resinosa, P. rigida, P. sabiniana, P. serotina, P. strobiformis, P. strobus, P. sylvestris, P. taeda, P. torreyana, P. virginiana, P. washoensis
Subordinate taxa
P. ponderosa var. arizonica, P. ponderosa var. ponderosa, P. ponderosa var. scopulorum
Synonyms P. tuberculata
Name authority Lemmon: Mining Sci. Press 64: 45. (1892) Douglas ex Lawson & C. Lawson: Agric. Man. 354. (1836)
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