Regularity: Regularly occurring
the Coastal, Transverse, and Peninsular ranges to the Mexican border
[10,34,35,39,41,55]. It is cultivated in Hawaii .
Regional Distribution in the Western United States
This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):
3 Southern Pacific Border
Occurrence in North America
age . It attains a height of 30 to 83 feet (9-25 m) and a d.b.h.
of 12 to 31 inches (30-80 cm) [23,29,31,41]. The bark is thick and
roughly furrowed at maturity [29,36,38]. The crown is pyramidal and may
be dense or open, depending upon the site [23,38,41]. Needles occur in
groups of three and are 6 to 12 inches (15-30 cm) long [29,41,50]. The
massive, spiny cones are 9 to 15 inches (24-40 cm) long, occurring in
whorls of four [29,41]. Young trees first bear cones on the trunk. As
trees mature, cones are also borne on strong branches .
Although geographically isolated, nine Coulter pine populations were
very similar in all of three morphological characteristics studies.
Oleoresins (volatile portion) were also similar .
Habitat and Ecology
Coulter pine occurs in a mediterranean climate. Winter rains are
infrequent, and the summer is dry with occasional summer thunderstorms
Coulter pine is most frequent on steep south-facing slopes and ridges
[4,22,52]. 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 [22,29,30]. Coulter pine occurs between 500 to 7,000
feet (150-2,120 m) elevation [47,55].
Key Plant Community Associations
Coulter pine occurs in a variety of plant associations, but seldom forms
extensive pure stands . Where they do occur, communities dominated
by Coulter pine intergrade with chaparral and lower montane coniferous
forest [5,24,27,47]. Coulter pine is named as a dominant species in the
following published classifications:
Terrestrial natural communities of California 
Vegetation types of the San Bernadino Mountains 
Vegetation of the San Bernadino Mountains 
A vegetation classification system applied to southern California 
Mixed evergreen forest 
Vascular plant communities of California 
Montane and subalpine forests of the Transverse and Peninsular ranges 
An introduction to the plant communities of the Santa Ana and San
Jacinto Mountains 
Associated trees not mentioned in Distribution and Occurrence include
sugar pine (Pinus lambertiana), bristlecone fir (Abies bracteata),
incense-cedar (Libocedrus decurrens), Sargent cypress (Cupressus
sargentii), black cottonwood (Populus trichocarpa), California bay
(Umbellularia californica), bigcone Douglas-fir (Pseudotsuga
macrocarpa), Pacific madrone (Arbutus menziesii), and birchleaf
mountain-mahogany (Cercocarpus betuloides var. betuloides)
[4,7,22,24,47,48,55]. Understory associates include chamise (Adenostoma
fasciculatum), Eastwood manzanita (Arctostaphylos glandulosa), Pringle
manzanita (A. pringlei), pointleaf manzanita (A. pugens), deerbrush
(Ceanothus integerrimus), annual hairgrass (Deschampsia danthonioides),
rareflower heterocodon (Heterocodon rariflorum), golden violet (Viola
douglasii), and annual ryegrass (Lolium multiflorum) [4,19,37,48,52].
This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):
More info for the term: shrub
FRES23 Fir - spruce
FRES28 Western hardwoods
FRES34 Chaparral - mountain shrub
Habitat: Cover Types
This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):
211 White fir
234 Douglas-fir - tanoak - Pacific madrone
246 California black oak
247 Jeffrey pine
248 Knobcone pine
249 Canyon live oak
250 Blue oak - Digger pine
255 California coast live oak
Habitat: Plant Associations
This species is known to occur in association with the following plant community types (as classified by Küchler 1964):
K006 Redwood forest
K020 Spruce - fir - Douglas-fir forest
K029 California mixed evergreen forest
K030 California oakwoods
K034 Montane chaparral
Habitat & Distribution
Fire Management Considerations
Intense fire may be responsible for reducing the distribution of Coulter
pine [52,57]. Fire intensity in chaparral, woodland, and forest
vegetation is probably greater since inititation of fire suppression
, and intense fire reduces Coulter pine populations. Frequent,
moderate-severity surface fires, however, would probably benefit this
species. The differential survival of large trees in less intensely
burned areas and enhanced reproduction on exposed mineral soil in such
areas both suggest that most Coulter pine evolved under a regime of
frequent, light- to moderate-severity surface fires . Managers
should keep in mind, however, that Coulter pine in Coulter pine-coast
live oak communities may be harmed by fire .
Prescribed burning has been used in Coulter pine/manzanita stands to
reduce fuel loading [11,51]. Severe fires or fires at too-frequent
intervals, however, convert such communities to mixed stands of
manzanita and ceanothus [52,55].
Frequent fire selects for Coulter pine over bigcone Douglas-fir in
canyon live oak (Quercus chrysolepis) communities .
Under long fire return intervals, Coulter pine invades oak savanna
Plant Response to Fire
Coulter pine readily establishes from seed on burned sites .
Persisting cones on surviving trees, and sometimes on those killed by
fire, provide a source of seed [38,52]. Seedling establishment is
usually greatest during the first postfire year . The severe Marble
Cone Fire in the Santa Lucia Mountains destroyed Coulter pine stands.
At postfire year 1, a large number of Coulter pine seeds germinated.
Three seasons following the fire, Coulter pine seedling density ranged
from 18 to 4,213 per acre (7-1,685/ha). The lower seedling densities
probably resulted from interference by annual ryegrass .
Vale  found that pine seedling density was much greater after the
Mt. Diablo fire than before it (newly-germinated pines could not be
identified by species). Pine seedling numbers were greatest in areas
where fire was less intense. In these areas, relative frequency of pine
seedlings was 100 percent; density was 2 seedlings per square meter. In
areas where fire was severe, relative frequency was only 56 percent, and
density was one seedling per square meter. Vale suggested that the
intense heat in the heavily burned areas may have destroyed seeds within
the cones of trees, but the less intense heat in the more lightly burned
areas may have opened cones without destroying seeds. Pine seedlings
were disproportionately located on areas where mineral soil was exposed.
Immediate Effect of Fire
Large Coulter pine are resistant to all but severe surface fires.
Younger trees are apparently killed by moderate-severity surface or
crown fires [23,54]. No data are available concerning the effect of
crown fire on large-diameter Coulter pine.
A "hot" surface fire on Mt. Diablo killed nearly all Coulter pine,
including large trees. In an area of the mountain where fire was less
severe, however, 9 of 52 Coulter pine survived. Of these trees, all of
those greater than 16 inches (40 cm) in d.b.h. survived, and only one
tree less than 16 inches in d.b.h. survived. Surviving trees had needle
scorch only on lower branches .
Tree without adventitious-bud root crown
Crown residual colonizer (on-site, initial community)
Serotiny is prevalent in Coutler pine/chaparral, Coulter pine-canyon
live oak, and Coulter pine/Sargent cypress communities. Cones of
Coulter pine in these communities typically do not open until heated by
fire. Consequently, the bulk of Coulter pine regeneration in these
communities occurs after fire. Coulter pine ecotypes associated with
coast live oak (Quercus agrifolia), however, typically bear cones that
open at maturity or shortly thereafter .
Coulter pine seedling development is best in mineral soil in open areas
. Such conditions are created by fire.
Facultative Seral Species
Coulter pine occurs in both initial communities and later seres. Stands
are often even-aged, establishing after fire [7,18,39]. Mature Coulter
pine is shade intolerant , but seedlings can grow in partial shade
At higher elevations of the Coast Ranges, Coulter pine sometimes
replaces blue oak (Quercus douglasii) .
Growth Form (according to Raunkiær Life-form classification)
interval between good seed crops is 3 to 6 years . Cones may
persist up to 5 or 6 years [31,41]. Seed dispersal is limited due to
the large size of seed. Seed viability is generally high. Seedling
establishment is best on mineral soil in full sun. Early growth is
rapid [7,23,31,38]. (See the Fire Ecology frame for a discussion of the
role of fire in Coulter pine regeneration.)
Life History and Behavior
More info for the term: ecotype
Coulter pine cones open for pollination in May and June [31,41,50].
Cones ripen in August and September of the second year following
pollination [29,31,50]. Mature cones may open at or soon after
maturity, slowly over a several-year peroid, or only after fire,
depending upon ecotype. Cones of nonserotinous ecotypes open and
disperse seed from October through Novermber [7,31,37].
Molecular Biology and Genetics
Barcode data: Pinus coulteri
Statistics of barcoding coverage: Pinus coulteri
Public Records: 6
Specimens with Barcodes: 15
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N4 - Apparently Secure
NatureServe Conservation Status
Rounded Global Status Rank: G4 - Apparently Secure
Coulter pine distribution has apparently decreased in recent years.
This may be due to past policies of fire suppression . See the Fire
Effects frame for a discussion on this problem.
Annual grasses deplete moisture from the top layer of soil, which
decreases survival of young Coulter pine [12,23]. Mature Coulter pine,
however, are drought tolerant .
Coulter pine cone processing and tree planting methods are discussed in
the literature [23,31]. A discussion of damaging agents can also be
found in the literature [1,7,21,28].
Relevance to Humans and Ecosystems
Importance to Livestock and Wildlife
insects almost exclusively on lower main trunks of Coulter pine, while
male white-headed woodpeckers extensively use the cones . The seeds
are also a dependable year-round food source for western gray squirrels
. Black-tailed deer rarely browse even young trees .
Wood Products Value
lumber [26,41,50]. It is light, weak, coarse-grained, and brittle .
The Coulter pine or big-cone pine, Pinus coulteri, is a native of the coastal mountains of Southern California and northern Baja California (Mexico). Isolated groves are found as far north as the San Francisco Bay Area in Mt. Diablo State Park and Black Diamond Mines Regional Preserve. The species is named after Thomas Coulter, an Irish botanist and physician.
Pinus coulteri is a substantial coniferous evergreen tree in the genus Pinus. The size ranges from 10–24 m (30–80 ft) tall, and a trunk diameter up to 1 m (3 ft). The trunk is vertical and branches horizontal to upcurved. The leaves are needle-like, in bundles of three, glaucous gray-green, 15–30 cm (6–12 in) long and stout, 2 mm (0.01 in) thick.
The outstanding characteristic of this tree is the large, spiny cones which are 20–40 cm (8–16 in) long, and weigh 2–5 kg (4-10 lbs) when fresh. Coulter pines produce the largest cones of any pine tree species (people are actually 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 has earned them the nickname "widowmakers" among locals.
This erect, medium-sized pine prefers south-facing slopes between 200–2300 m (600-7,500 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. Woodpeckers often forage on the species, and peel the bark to access insects underneath.
The wood is weak and soft, so that the species is little used other than for firewood.
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.
- Farjon, A. (2011). "Pinus coulteri". IUCN Red List of Threatened Species. Version 3.1. International Union for Conservation of Nature. Retrieved 2013-11-10.
- Gymnosperm Database, 2008
- Forest Service
- C. Michael Hogan, 2008
- Moore, Gerry; Kershner, Bruce; Craig Tufts; Daniel Mathews; Gil Nelson; Spellenberg, Richard; Thieret, John W.; Terry Purinton; Block, Andrew (2008). National Wildlife Federation Field Guide to Trees of North America. New York: Sterling. p. 86. ISBN 1-4027-3875-7.
- "RHS Plant Selector Pinus coulteri AGM / RHS Gardening". Apps.rhs.org.uk. Retrieved 2013-09-27.
- Conifer Specialist Group (1998). Pinus coulteri. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 12 May 2006.
- Gymnosperm Database (2008) Pinus coulteri
- Flora of North America: Pinus coulteri
- C. Michael Hogan (2008) Pinus coulteri, pub: Globaltwitcher.com, ed: Nicklas Stromberg
- Chase, J. Smeaton (1911). Cone-bearing Trees of the California Mountains. Chicago: A. C. McClurg & Co. p. 99. LCCN 11004975. OCLC 3477527. LCC QK495.C75 C4, with illustrations by Carl Eytel - Kurut, Gary F. (2009), "Carl Eytel: Southern California Desert Artist", California State Library Foundation, Bulletin No. 95, pp. 17-20 retrieved Nov. 13, 2011
Names and Taxonomy
California Coulter pine