Coulter pine Pinus coulteri
A Pinus coulteri seed cone at Mount Wilson, California
Conservation status
Near Threatened  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Gymnospermae
Division:	Pinophyta
Class:	Pinopsida
Order:	Pinales
Family:	Pinaceae
Genus:	Pinus
Subgenus:	P. subg. Pinus
Section:	P. sect. Trifoliae
Subsection:	P. subsect. Ponderosae
Species:	P. coulteri
Binomial name
Pinus coulteri D. Don
Natural range

Coulter pine (Pinus coulteri), or big-cone pine, is a conifer in the genus Pinus of the family Pinaceae. Coulter pine is a native evergreen conifer that lives up to 100 years of age. ^[2] Coulter pine occurs in a mediterranean climate. Winter rains are infrequent, and the summer is dry with occasional summer thunderstorms.^[3] It is a native of the coastal mountains of Southern California in the United States and northern Baja California in Mexico. Isolated groves are found as far north as Clearlake, California on the flanks of Mt. Konocti and Black Diamond Mines Regional Preserve. Although it has a limited range in the wild, the Coulter pine is a popular ornamental tree and is grown in many countries. Although geographically isolated, these Coulter pine populations were very similar in all of three morphological characteristics studies.Oleoresins (volatile portion) were also similar.^[4]

Coulter pine (Pinus coulteri) is named after Thomas Coulter, an Irish botanist and physician. The Coulter pine produces some of the heaviest cones of any pine tree, up to 5 kg (11 lb) and among conifers is exceeded only by the cones of Araucaria bidwillii.

Pinus coulteri is a substantial coniferous evergreen tree in the genus Pinus. The size ranges from 10–24 m (33–79 ft) tall,^[5] and a trunk diameter up to 1 m (3.3 ft). The trunk is vertical and branches horizontal to upcurved. Bark dark gray-brown to near black, deeply furrowed, with long, scaly, irregularly anastomosing, rounded ridges.^[6] The crown is pyramidal and may be dense or open, depending upon the site.^[2] The leaves are needle-like, in bundles of three, glaucous gray-green, 15–30 cm (5.9–11.8 in) long and stout, 2 mm (0.079 in) thick.^{[citation needed]}

The outstanding characteristic of this tree is the large, spiny cones which are 20–40 cm (7.9–15.7 in) long (occasionally as much as twenty inches (51 centimeters) length has been observed),^[7] 23 centimeters (nine inches) in width,^[8] and weigh 2–5 kg (4.4–11.0 lb) when fresh. Each segment, or "scale", of the cone is tipped with a talon-like hook. Coulter pines produce the largest cones of any pine tree species and people are advised to wear hardhats when working in Coulter pine groves, although the slender cones of the sugar pine are longer. The large size of the cones, combined with the claw-like scales, has earned them the nickname "widowmakers" among locals.^{[citation needed]}Seed cones maturing in 2 years, gradually shedding seeds thereafter and moderately persistent, massive, heavy, drooping, asymmetric at base, narrowly ovoid before opening, ovoid-cylindric when open, 20-35 cm, pale yellow-brown, resinous, stalks to 3cm; apophyses transverse-rhombic, strongly and sharply cross-keeled, elongate, curved, continuous with umbos to form long, upcurved claws 2.5-3 cm. Seeds obovoid; body 15-22 mm, dark brown; wing to 25 mm. 2n=24".^[6]

The name Pinus coulteri comes from Latin for pine, and coulteri comes from its discoverer Thomas Coulter (1793–1843), an Irish botanist and physician.^[9] Pinus coulteri was discovered by Dr. Coulter on the mountains of Santa Lucia, near the Mission of San Antonio, in latitude 36°, within sight of the sea and at an elevation of from 3000 to 4000 feet above its level. It was growing intermingled with Pinus Lambertiana.^[10]

This is a member of subsection Ponderosae, and is generally recognized as closely related (morphologically, geographically, and genetically) to Pinus sabiniana, P. torreyana, and P. jeffreyi; the three taxa form group Sabinianae Loudon 1838 (Pinus jeffreyi, though morphologically a bit different, is known to hybridize with P. coulteri, and molecular analysis clearly places it in the Sabinianae).^[11] P. coulteri, alone in the Sabinianae, also shares a chlorplast haplotype with P. arizonica of the northern Sierra Madre. It seems likely that the species arose through a hybridization event involving two members of subsection Ponderosae. ^[11]

An introduction to the plant communities of the Santa Ana and San Jacinto Mountains.^[12] Coulter pine is most frequent on steep south-facing slopes and ridges.^[13][14][15] Soils may be poor to fertile, and are typically dry. Coulter pine is an indicator of serpentine soils, but also occurs on a variety of other substrates.  Soils range from loamy to gravelly or rocky in texture.^[15][16][17] Coulter pine occurs between 500 to 7,000 feet (150-2,120 m) elevation.^[18][19]

Coulter pine is the dominant species in the following published classifications: Terrestrial natural communities of California,^[15] Vegetation types of the San Bernadino Mountains,^[20] Vegetation of the San Bernadino Mountains,^[3] A vegetation classification system applied to southern California,^[21] Mixed evergreen forest,^[22] Vascular plant communities of California,^[18] Montane and subalpine forests of the Transverse and Peninsular ranges.^[23]

The Coulter pine is closely related to the foothill pine, Pinus sabiniana. It is more distantly related to Jeffrey pine with which it shares habitats, and the ponderosa pine.^[24] Coulter pines tend to grow in drier environments than ponderosa and Jeffery pines.^{[citation needed]}

This erect, medium-sized pine prefers south-facing slopes between 200–2,300 m (660–7,550 ft) elevation, and tolerates dry rocky soil. Pinus coulteri most often appears in mixed forests. The Coulter pine occurs in a number of forest plant associations; for example, at higher elevations forestation of the San Jacinto Mountains Coulter Pine is co-dominant with the California black oak.^[25] Woodpeckers often forage on the species, and peel the bark to access insects underneath.^[26]

Wildlife, especially squirrels, gather the large seeds. They were also once eaten by Native Americans.^[27]

The wood is weak and soft, so that the species is little used other than for firewood.^{[citation needed]}

Pinus coulteri is cultivated as an ornamental tree, planted in parks and large gardens, and drought tolerant landscaping. The Coulter pine has gained the Royal Horticultural Society's Award of Garden Merit.^[28]

• 
  Pollen cones (male cones)
• 
  Mature tree, as seen from under branches at ground level
• 
  Close-up of bark detail
• 
  Foliage and cones
• 
  Cones on ground in their natural setting
• 
  Large cone, found at 4,150 ft elevation in the Santa Lucia Ranger District of the Los Padres National Forest, California Coastal Range of the Central Coast.
• 
  Exceptional cone example, shown with needle cluster (soda can for scale).
• 
• 
  Cone
• 
  Close-up of spiral detail
• 
  Close-up of barb detail
• 
• 
  Seeds
• 
  A view of the upper portion of a mature Coulter Pine.

• Chase, J. Smeaton (1911). "Pinus Coulteri (Coulter-pine, Big-cone-pine, Pitch-pine, Bull-pine)". Cone-bearing Trees of the California Mountains. Eytel, Carl (illustrations). Chicago: A.C. McClurg & Co. pp. 24–26. LCCN 11004975. OCLC 3477527.
• Cope, Amy B. (1993). "Pinus coulteri". Fire Effects Information System (FEIS). US Department of Agriculture (USDA), Forest Service (USFS), Rocky Mountain Research Station, Fire Sciences Laboratory.
• Earle, Christopher J., ed. (2018). "Pinus coulteri". The Gymnosperm Database.
• Farjon, A. (2013). "Pinus coulteri". IUCN Red List of Threatened Species. 2013: e.T42352A2974687. doi:10.2305/IUCN.UK.2013-1.RLTS.T42352A2974687.en.
• Kral, Robert (1993). "Pinus coulteri". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 2. New York and Oxford: Oxford University Press – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
• Hogan, C. Michael (2008). Stromberg, Nicklas (ed.). "Pinus coulteri". Globaltwitcher.com. Archived from the original on 2012-02-18.
• Moore, Gerry; Kershner, Bruce; Tufts, Craig; Mathews, Daniel; Nelson, Gil; Spellenberg, Richard; Thieret, John W.; Purinton, Terry; Block, Andrew (2008). National Wildlife Federation Field Guide to Trees of North America. New York: Sterling. p. 86. ISBN 978-1-4027-3875-3.
• "Pinus coulteri". RHS Gardening. Royal Horticultural Society. Retrieved 2013-09-27.^{[permanent dead link]}

Wikimedia Commons has media related to Pinus coulteri
(Coulter pine).

• Calflora
• Jepson Manual Treatment
• USDA Plants Profile for Pinus coulteri (Coulter pine)
• Pinus coulteri in the CalPhotos photo database, University of California, Berkeley