Regularity: Regularly occurring
Regularity: Regularly occurring
Global Range: Orange, Riverside and San Diego Counties, Californa; northern Baja California, Mexico. Range extent in California is about 580 sq miles in 2 main sections. The extent in Baja is not known.
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
cypress species . There are about 15 known populations [6,7].
Tecate cypress occurs in four groves in southern California. Three of
the groves are in San Diego County on Guatay Mountain, Otay Mountain,
and Tecate Peak. The fourth is on Sierra Peak in the Santa Ana
Mountains of Orange County [2,12,40]. Isolated groves of Tecate cypress
extend about 150 miles (240 km) south into peninsular Baja California .
Tecate cypress is cultivated in Hawaii .
Tecate cypress is a native, evergreen tree with a bushy growth form.
Most trees are multitrunked, generally without a dominant leader
[10,25,40]. Tecate cypress generally grows from 20 to 23 feet (6-7 m)
tall, but can be as tall as 33 feet (10 m) [10,40]. On sites with a
high cypress seedling density, Tecate cypress can be dwarfed and may
only reach heights of 3 to 6 feet (1-2 m) at maturity [33,39]. Mature
leaves are 0.06 inch (1.5 mm) long, although they can be up to 0.4 inch
(10 mm) long on vigorous shoots . Ovulate cones are solitary and up
to 1.2 inches (30 mm) long. Staminate cones are 0.12 to 0.16 inch (3-4
mm) long [10,24,40]. The bark is nonfibrous, exfoliating, and only
about 0.4 inch (1 cm) thick [10,40]. Tecate cypress forms a
well-defined taproot and numerous laterals the first year [13,40]. It
can survive in a vigorous condition to an age of about 90 years .
The oldest known Tecate cypress tree is located in the Sierra Peak grove
and is 209 years old .
Catalog Number: US 669800
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Verified from the card file of type specimens
Preparation: Pressed specimen
Collector(s): C. N. Forbes
Year Collected: 1907
Locality: San Diego, California, United States, North America
- Isotype: Jepson, W. L. 1922. Madrono. 1: 75.
Habitat and Ecology
Comments: Ravines, gulches and ridges on dry mountain slopes in chaparral where the Silverado soil formation is exposed (calcareous), closed-cone coniferous forest.
materials include sandstone, granite, and conglomerate [1,40]. Soils
are usually well drained. Tecate cypress is commonly found on dry
slopes, exposed hillsides, and ridgetops, but also grows along
streambanks and arroyos [7,10,21]. It is generally found at elevations
from 1,500 to 5,000 feet (450-1500 m), but occurs at 8,000 feet (2,425
m) on Guatay Mountain [1,10,24].
Key Plant Community Associations
Tecate cypress is a component of the southern interior cypress forest.
This community is a dense, fire-maintained, low forest that forms
even-aged stands surrounded by a matrix of chaparral [11,15]. In San
Vicente, Mexico, Tecate cypress grows with bishop pine (Pinus muricata)
. Tecate cypress is also associated with closed-cone coniferous
Publications naming Tecate cypress as a community dominant are listed
Preliminary descriptions of the terrestrial natural communities of
The closed-cone pines and cypress 
Vegetation change in chaparral and desert communities in San Diego
County, California 
Woody species not previously mentioned but commonly associated with
Tecate cypress include California scrub oak (Quercus dumosa), shrub live
oak (Q. turbinella), Eastwood manzanita (Arctostaphylos glandulosa),
bigberry manzanita (A. glauca), Otay manzanita (A. otayensis), mission
manzanita (Xylococcus bicolor), hoaryleaf ceanothus (Ceanothus
crassifolius), wedgeleaf ceanothus (C. cuneatus), cupleaf ceanothus (C.
greggi var. perplexans), woolyleaf ceanothus (C. tomentosus var.
olivaceus), chamise (Adenostoma fasciculatum), lemonade sumac (Rhus
integrifolia), sugar sumac (R. ovata), laurel sumac (Malosma laurina),
toyon (Heteromeles arbutifolia), curlleaf mountain-mahogany (Cercocarpus
betuloides), California sagebrush (Artemisia californica), rushrose
(Helianthemum scoparium), redberry (Rhamnus crocea), southern bush
monkeyflower (Mimulus longiflorus), Parry nolina (Nolina parryi),
whiteflower currant (Ribes indecorum), San Diego mountain misery
(Chamaebatia australis), hollyleaf cherry (Prunus ilicifolia), wooly
bluecurls (Trichostema lanatum), bushrue (Cneoridium dumosum), black
sage (Salvia mellifera), white sage (S. apiana), fragrant sage (S.
clevelandii), Munz's sage (S. munzii), heart-leaved pitcher sage
(Lepechinia cardiophylla), fragrant pitcher sage (L. fragrans),
chaparral pea (Pickeringia montana ssp. tomentosa), hairy yerba santa
(Eriodictyon trichocalyx), yerba santa (E. crassifolium), tree poppy
(Dendromecon rigida), chaparral yucca (Yucca whipplei), saw-toothed
goldenbush (Hazardia squarrosa), and Mexican flannelbush
(Fremontodendron mexicanum) [1,7,31,39].
Herbaceous species not previously mentioned but commonly associated with
Tecate cypress include eucrypta (Eucrypta micrantha), bluedick (Brodiaea
pulchella), fire poppy (Papaver californicum), Catalina Mariposa lily
(Calochortus catalinae), Dunn's Mariposa lily (C. dunii), scarlet
delphinium (Delphinium cardinale), star flower (Enastrum sapphirinum),
prickly-phlox (Leptodactylon californicum), California buckwheat
(Eriogonum fasciculatum), golden-yarrow (Eriophyllum confertiflorum),
California poppy (Eschscholzia californica), intermediate cryptantha
(Cryptantha intermedia), and Fremont deathcamas (Zigadenus fremontii)
Habitat: Cover Types
This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):
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):
K030 California oakwoods
K035 Coastal sagebrush
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):
FRES28 Western hardwoods
FRES34 Chaparral - mountain shrub
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 6 - 20
Comments: 22 EO's are known, but 10 are historic. More may be historic or extirpated now, and the CNDDB may not know.
Fire Management Considerations
Although fire is important for releasing seed and preparing seedbeds for
Tecate cypress establishment, fires occurring too frequently in Tecate
cypress groves may destroy them by eliminating reproduction. Up to a
point, reproductive success increases with an increase in the fire-free
interval , but fire must occur before tree senesce or the trees fail
Cone production begins at an early age and cones accumulate on trees;
because of greater productivity and accumulated cone crops, postfire
seedling establishment is greater in stands over 50 years of age at the
time of burning than in stands less than 50 years . Data from three
studies were combined to estimate the rate of Tecate cypress first-year
seedling density as a percentage of prefire stem density. By about 36
years of age, Tecate cypress reproduction density, if the stand is
burned, can equal or exceed that of the original stand :
Stand age (yrs.) Reproductive rate (%) Source
10 negligible 
19 0.1 
20 2.9 
20 26.5 
30 15.7 
36 1206.5 
39 1387.3 
63 1400.0 
Fires at intervals of less than 35 to 40 years would be likely to reduce
stand density .
Zedler  suggested that Tecate cypress populations on Tecate Peak and
Otay Mountain have declined because of increased numbers of human-caused
fires. Stands burned after 21 and 28 years have marked declines in
density . Stands 28 and 34 years old did not reestablish vigorously
enough to maintain prefire densities. Zedler  stated that the
necessary fire-free interval is greater than 40 years, and therefore
longer than the current 25-year fire interval reported by Armstrong .
On north-facing slopes of Tecate Peak, two stands burned in 1880, 1944,
and 1975 . One stand (Smuggler's Canyon) also burned in 1965.
Estimated Tecate cypress densities are shown below:
Smuggler's Canyon Bigrock Stand
Year Time since cypress Time since cypress
last fire (yrs.) trees/sq m* last fire (yrs.) trees/sq m*
1943 no data no data 63 (1.0)
1945 0.5 (1.5) 0.5 (>14.0)
1965 11 > 1.4 no data no data
1966 0.5 (0.04) no data no data
1972 7 0.03 28 8.9
1976 1 0.02 1 1.4
* Figures in parentheses are estimates based on extrapolation from other
stands of similar age; estimates of density are conservative.
In the past 67 years the fire frequency on Tecate Peak has gone from
one fire every 40+ years to one fire every 15 years in some areas. In
the same period, the average extent of Tecate cypress has dropped from
260 acres (105 ha) to 74 acres (31 ha) . On the Smuggler's Canyon
site, Tecate cypress has been reduced in less than 35 years from a
dominant to a minor vegetational component . The decline in density
has not been as drastic in the Bigrock Stand because of one less fire in
Dunn  has proposed the following fire frequency categories and
subsequent responses by Tecate cypress:
high (1-25 years)- elimination of Tecate cypress from plant community
moderate (26-39 years)- unlikely to maintain present range of Tecate cypress
low (40+ years)- maintenance of Tecate cypress population
Tree without adventitious-bud root crown
Crown residual colonizer (on-site, initial community)
Initial-offsite colonizer (off-site, initial community)
Tecate cypress is a fire-adapted, fire-dependent species [7,39,42]. It
exhibits adaptations that indicate "strict dependence on fires of a
particular frequency". These adaptations include serotinous cones,
resinous foliage that is highly flammable when dry, thin bark, and a
mixed chaparral habitat that ensures heavy fuels and a fuel ladder into
the canopy when trees are at their reproductive peak (age 40+ years).
Before this age, the biomass of the community is lower, and there is
considerably less dead material in and under the canopy. At about age
40 years, the cypress begin completely overtopping the shrub species,
limiting the availability of light to the shrubs. This period, when the
base of the cypress canopy is at about the same level as the top of the
shrub canopy, is the time of greatest flammability in the stand. At 80
postfire years, stand flammability may decrease because a closed-canopy
stand of Tecate cypress, almost devoid of an understory, develops
Cypress trees of southern California have serotinous cones that persist
on trees for years [17,44]. Some Tecate cypress cones remain on trees
for over 8 years . Cone opening in the California cypress species
is erratic and almost negligible except when cones are exposed to
extreme heat; then it is rapid and uniform . When opened by the
heat of a fire, the seeds fall on exposed mineral soil [17,40]. Most
seed falls in the first months following fire . When fires occur in
late summer and fall and are followed by winter rains, seed is
disseminated on moist, bare mineral substrates. These are optimum
conditions for cypress seed germination . Successful Tecate cypress
reproduction is generally restricted to burned sites [19,42,43] or to
washes where seeds have germinated after water dispersal .
According to Armstrong , Tecate cypress has had an average interval
between fires of 25 years during the last century, with a range of 15 to
63 years [1,39]. However, Keeley  estimated natural fire frequency
from 50 to 100 years for Tecate cypress communities based on
reproductive rate data [1,7,41].
More info for the terms: competition, shrubs
Facultative Seral Species
Site requirements for cypress seedlings are typical of those for pioneer
conifers. Seedlings are shade intolerant and survive best in full
sunlight on bare mineral soil [1,39]. The primary period for Tecate
cypress population expansion is during the first 1 or 2 postfire years
. According to Armstrong , cypress trees of southern California
are sensitive to lack of light, losing their foliage when growing in
Chaparral species inhibit the establishment of cypress seedlings on
most sites due to competition. However, many chaparral species are less
able to compete on infertile soils where Tecate cypress is often found.
On these sites, shrubs are stunted and sparse [1,2].
Tecate cypress reproduces exclusively from seed. Cone production is
abundant. Staminate cones are produced on trees that are 6 to 7 years
old . Ovulate cones are produced on trees that are 5 to 7 years of
age or older, but production is sporadic until age 30 [7,40]. Maximum
cone production occurs on trees that are 40 to 50 years old [7,14,41].
The cones require 2 years to mature . The cones of California
cypress are closed; they usually persist on the tree until opened by the
heat of a fire or from desiccation due to age [13,39]. The cones open,
however, when mechanically detached from the tree, with the resinous
seals breaking as the cones dry. In 1964, 167 unopened Tecate cypress
cones were collected from Sierra Peak; 2 years later, 58 percent of the
cones had opened and shed seeds while 42 percent remained unopened.
Most of the unopened cones had slightly separated scales with trapped
seeds. The trapped seeds probably lost their viability because of
desiccation. Attached cones have remained closed for over 8 years.
Sierra Peak Tecate cypress cones, some of them estimated to be 25 to 30
years old, were seen partially enveloped by exfoliating bark .
Seeds are shed gradually over several months after the cones open .
Seeds shed from detached cones rarely result in seedling establishment,
usually due to lack of a suitable seedbed . Seed dispersal is
primarily by wind and rain .
Cypress seeds require bare mineral soil for germination and
establishment. Seedling mortality is high on shaded sites with abundant
litter because of damping-off fungi [1,39]. Seedlings are sensitive to
excessive moisture .
Growth Form (according to Raunkiær Life-form classification)
Life History and Behavior
Tecate cypress growing in the Eddy Arboretum in Placerville, California,
sheds pollen in October and November . On Tecate Peak, male
strobili are mature by mid-October. Pollination occurs in late summer
and fall, 6 months after other southern California cypress species .
Seeds mature 15 to 18 months after pollination. Ovulate cones remain
closed until opened by heat or age [1,39].
Molecular Biology and Genetics
Statistics of barcoding coverage: Callitropsis forbesii
Public Records: 0
Specimens with Barcodes: 6
Species With Barcodes: 1
Barcode data: Hesperocyparis forbesii
Statistics of barcoding coverage: Hesperocyparis forbesii
Public Records: 3
Specimens with Barcodes: 3
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1998Vulnerable(Oldfield et al. 1998)
- 1997Vulnerable(Walter and Gillett 1998)
National NatureServe Conservation Status
Rounded National Status Rank: N2 - Imperiled
Rounded National Status Rank: N2 - Imperiled
NatureServe Conservation Status
Rounded Global Status Rank: G2 - Imperiled
Reasons: Cupressus forbesii is known from a very narrow range and from only a few extant occurrences (perhaps fewer than 12 in California). Its habitat contains other unique taxa. Development is a major threat to this species. Also, wildfires can be a threat if they occur too frequently, which they have in recent years. The pace of extirpation is increasing for this plant and its status in California is becoming critical. Several sites are on public lands including BLM and USFS, but it is possible none are protected.
Environmental Specificity: Narrow. Specialist or community with key requirements common.
Comments: Known from 2 smallish areas in California and apparently some in Baja.
rare or endangered in California .
Global Short Term Trend: Decline of 30-50%
Comments: Short term trend has been one of steady and rapid decline due to numerous threats.
Global Long Term Trend: Decline of 70-90%
Comments: Long term trend has been one of severe decline.
Degree of Threat: Very high - high
Comments: Threatened by frequent wildfires, development, mining, grazing and roads.
Biological Research Needs: Best management strategies for fire use with this taxon; controlled burning.
Grazing and trampling by livestock are detrimental to cypress seedlings.
Fire followed by intensive grazing could eliminate a cypress grove [1,2].
Strip mining for underlying clay deposits has destroyed a large portion
of the Sierra Peak Tecate cypress grove. Continuation of these
operations could eliminate this grove [2,38]. Most southern California
Tecate cypress groves are threatened by fire and development [10,31].
Tecate cypress seedlings are susceptible to damping-off fungi .
Tecate cypress has a low susceptibility to coryneum canker (Coryneum
cardinale), which can kill trees. Fungicides are effective in
preventing the spread of the disease but cannot eradicate it once
infection has begun [13,40].
Relevance to Humans and Ecosystems
Value for rehabilitation of disturbed sites
soil erosion . In interior California and near the coast, Tecate
cypress is used for hedges and windbreaks for citrus orchards .
Tecate cypress forests provide cover for mountain lions and golden
Importance to Livestock and Wildlife
undesirable forage for livestock, although young plants are occasionally
browsed . Tecate cypress forests are considered prime habitat for
the San Diego coast horned lizard .
Wood Products Value
Cypress (Cupressus spp.) wood is generally durable and stable. It is
suitable for a wide range of exterior uses including joinery, shingles,
and boats. Possible interior uses include moulding and panelling .
Tecate cypress has been cut for fenceposts [2,40]. Cypress shelterbelts
provide good firewood. Most cypress species develop a large proportion
of heartwood which splits well, dries quickly, and is clean burning.
Cypress wood is moderately fast burning because of its medium density.
As cypress woods are prone to sparking, they are recommended only for
enclosed fires .
Cupressus forbesii is native to chaparral and woodlands habitats and grows at 450–1,500 metres (1,480–4,920 ft).  It found in the western Peninsular Ranges in: Orange and San Diego Counties in Southern California; and northern Baja California, Mexico. 
The northernmost stand, in Orange County, which comprises a large area on the upper limits of Coal Canyon and Sierra Peak in the Santa Ana Mountains, burned in a 2006 wildfire. Very few mature trees survived but regeneration is occurring by the hundreds to thousands. However another wildfire before trees are able to reach cone-producing age, which can be quite old for this species, could extirpate the stand.
Cupressus forbesii reaches 10 metres (33 ft), and is usually without dominant terminal shoot resulting in a multi-trunked tree. The foliage ranges from rich light green to green, and seed cones are dark brown, 20–32 mm. 
Cupressus forbesii has in the past been referred to as Cupressus guadalupensis var. forbesii. This taxonomy has been somewhat controversial, as morphology and molecular testing have both shown Cupressus guadalupensis to be genetically distinct enough from Cupressus forbesii to warrant being placed in its own species. Cupressus guadalupensis is endemic to Guadalupe Island off Baja California, two hundred fifty miles away from any C. forbesii stands. Molecular testing has shown Cupressus guadalupensis to be slightly more closely related to Cupressus stephensonii.
Major differences between Tecate Cypress (Cupressus forbesii) and Guadalupe Cypress (Cupressus guadalupensis) are:
- Guadalupe Cypress, when mature, makes a much more massive and taller tree than Tecate Cypress.
- Guadalupe Cypress has glaucous, somewhat blue-tinted foliage, while Tecate Cypress has very green foliage.
- Guadalupe Cypress cones will open without fire, while Tecate Cypress cones differ from any other species of California Cypress, in that even once disconnected from the parent tree, they will not open without heat.
Cupressus forbesii has proven to be a successful specimen tree, tolerant of the California Coastal climate and its cool temperatures and humidity, where other inland-growing Cypress species such as Cupressus macnabiana have done poorly in these conditions. A Tecate Cypress planted at Strybing Arboretum in San Francisco is showing vigor and produces viable cones at forty years of age.
- California chaparral and woodlands - (ecoregion)
- California montane chaparral and woodlands- (subecoregion)
- conifers.org: Cupressus forbesii. Accessed 12 November 2010.
- Jepson Manual
- Lee, M. Rare Otay butterfly doesn't make 'endangered' list. San Diego Union-Tribune February 22, 2011.
- Little, D.P. 2006. Evolution and circumscription of the true cypresses (Cupressaceae: Cupressus). Systematic Botany 31(3): 461-480.
- Wolf, C. B. & Wagener, W. E. (1948). The New World cypresses. El Aliso 1: 195-205.
Names and Taxonomy
Comments: Treated as a species by Kartesz (1994 and 1999), and as a variety of Cupressus guadelupensis by Little (1971 atlas). Considered native but not endemic in California by Kartesz (1999).
Cupressus forbesii Jeps. (Cupressaceae) [10,24,40].
Cupressus guadalupensis Wats. var. forbesii (Jeps.) Little [48,48]
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