Knobcone pine (Kral 1993).
Syn: Pinus tuberculata Gordon 1849, not D.Don 1836; P. tuberculata var. acuta Mayr (Millar 1986, Kral 1993).
Tree to 24 m tall or, on very poor sites, a shrub; dbh to 80 cm, trunk usually straight; crown usually 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, shoots slender, red-brown. Leaves three per fascicle, spreading or ascending, persisting 4-5 years, (8-)9-15(-20) cm × (1-)1.3-1.8 mm, straight or slightly curved, twisted, yellow-green, all surfaces with fine stomatal lines, margins serrulate, apex abruptly conic-subulate; sheath (1)1.5-2 cm, base persistent. Buds ovoid to ovoid-cylindric, dark red-brown, aging darker, ca. 1.5 cm, resinous; scale margins fringed, apex attenuate. Pollen cones ellipsoid-cylindric, 10-15 mm long, orange-brown. Seed cones remain closed for 20 years or more, or open on burning; in whorls, hard and heavy, very asymmetric, lanceoloid before opening, ovoid-cylindric when open, 8-16 cm, yellow-brown or pale brown, sessile or on a peduncle to 1 cm; maturing in 2 years. Cone scales with 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. 6-7 mm, nearly black; wing narrow, to 20 mm. 2n=24 (Kral 1993, M.P. Frankis e-mail 1999.03.06).
USA: Oregon & California, specifically: "In the Coast Range maountains of southern Oregon and northern California (on the Siskiyou Mountains, Trinity Alps, Mount St. Helena Summit, etc.), on the Santa Cruz Mountains, on Point Pinos, near Carmel, Monterey County, and the eastern slopes of the Santa Lucia Mountains, Monterey County; on Mount Shasta (4000 to 5600 feet); on the west slopes of the northern Sierra Nevada, at 1500 to 4500 feet, south to the south side of the San Bernardinos at 2500 to 4000 feet. Lacking otherwise in the southern Sierra Nevada and southern Coast Ranges (Peattie 1950). Also in Mexico: Baja California Norte. Fire successional on dry slopes and foothills (Kral 1993). Hardy to Zone 7 (cold hardiness limit between -17.7°C and -12.2°C) (Bannister and Neuner 2001). See also Thompson et al. (1999).
The former champion fell in 2010 (Luke Ruediger e-mail 2011.05.08); it was 109 cm dbh, 36 m tall, crown spread 20 m, located in Shasta County, CA (American Forests 1996). The California big tree registry has not named a new champion, but Oregon's largest tree is 95 cm dbh, 35.6 m tall, and has a crown spread of 15.5 m (Ascending the Giants 2011).
In cultivation in Britain not known to exceed about 80 years (M.P. Frankis e-mail 1999.06.03).
USDA hardness zone 7 (inland Oregon origins), otherwise zone 8.
Besides the specific range notes given above, Arno and Gyer (1973) specify several locales around Yosemite National Park and it is also found in dry associations with Sequoia sempervirens at Redwood National Park (ICE Flora and Fauna Database).
"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" (Kral 1993).
This species is the only common host of the dwarf mistletoe Arceuthobium siskiyouense (Hawksworth and Wiens 1996).
Lemmon, J.G. 1892. Notes on West American Coniferae. Mining Sci. Press 64:45. Lemmon also described the species a few weeks later (1892.01.16 vs. 1892.02.10) in a much more readily available journal:
Lemmon, J.G. 1892. Notes on cone-bearers of north-west America. Garden and Forest 5(207):64-65. Available by a search at the Library of Congress, accessed 2011.03.20.
Millar, C.I. 1986. The Californian closed-cone pines; a taxonomic history and review. Taxon 35: 657-670.
This page co-edited with M.P. Frankis, 1999.03.
Last Modified 2017-11-07