Pinus attenuata

Lemmon

Mining Sci. Press 64: 45. 1892.

Common names: Knobcone pine
Basionym: Pinus tuberculata Gordon 1849,
Treatment appears in FNA Volume 2.

Shrubs or trees to 24m; trunk to 0.8m diam., usually straight; crown mostly narrowly to broadly conic. Bark purple-brown to dark-brown, shallowly and narrowly fissured, with irregular, flat, loose-scaly plates, on upper sections of trunk nearly smooth. Branches ascending; twigs slender, redbrown. Buds ovoid to ovoid-cylindric, dark redbrown, aging darker, ca. 1.5cm, resinous; scale margins fringed, apex attenuate. 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. Pollen cones ellipsoid-cylindric, 10–15mm, orangebrown. Seed-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 redbrown, 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. Seeds compressed-oblique-obovoid; body ca. 6–7mm, nearly black; wing narrow, to 20mm. 2n =24.


Habitat: Fire successional on dry slopes and foothills of Sierra Nevada and the Cascade and Coast ranges
Elevation: 300–1200m

Distribution

V2 38-distribution-map.gif

Calif., Oreg., Mexico in Baja California

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.

Selected References

None.

Lower Taxa

None.

"relatively thin" is not a number.

... more about "Pinus attenuata"
resinous +
conic-subulate +  and attenuate +
rhombic +, raised-angled-conic +  and mammillate +
Robert Kral +
Lemmon +
purple-brown;dark-brown +
fissured +
persistent +
elongate +
Pinus tuberculata +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
resinous +
darker +  and dark redbrown +
conspicuous +
ovoid;ovoid-cylindric +
1.5 cm15 mm <br />0.015 m <br /> (?) +
Knobcone pine +
pale redbrown;yellow +
8 cm80 mm <br />0.08 m <br /> (15 cm150 mm <br />0.15 m <br />) +
long-persistent +
ovoid-cylindric +  and lanceoloid +
Calif. +, Oreg. +  and Mexico in Baja California +
300–1200m +
sheathed +  and sessile +
rounded +, 2-3-angled +  and terete +
Fire successional on dry slopes and foothills of Sierra Nevada and the Cascade and Coast ranges +
arranged +  and fascicles +
15 cm150 mm <br />0.15 m <br /> (20 cm200 mm <br />0.2 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
yellow-green +
curved +  and straight +
persisting +
9 cm90 mm <br />0.09 m <br /> (15 cm150 mm <br />0.15 m <br />) +
ascending;spreading +
4 (?) +  and 5 (?) +
scale-like +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not winged +  and 2-winged +
ellipsoid-cylindric +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Mining Sci. Press +
fibrous;woody +
arranged +  and overlapping +
persistent +
flattened +
pliable +  and woody +
grouped +  and solitary +
long-persistent +
wingless +, winged +, stalked +  and sessile +
persistent +
pendent;more or less erect +
compressed-oblique-obovoid +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
reduced;well-defined short +
1 cm10 mm <br />0.01 m <br /> (?) +
extended +
Apinus +, Strobus +  and Caryopitys +
Pinus attenuata +
species +
decurrent +  and elongate +
straight +
slender +
sharp +  and low-pyramidal +
tree +  and shrub +
reduced +
0 cm0 mm <br />0 m <br /> (?) +  and 2 cm20 mm <br />0.02 m <br /> (?) +