Cupressus forbesii

Cupressus forbesii
One of the very few Cupressus forbesii that survived the Feb. 2006 fire at Coal Canyon, Cleveland National Forest
Conservation status
Vulnerable (IUCN 2.3)
Scientific classification
Kingdom:	Plantae
Division:	Pinophyta
Class:	Pinopsida
Order:	Pinales
Family:	Cupressaceae
Genus:	Cupressus
Species:	C. forbesii
Binomial name
Cupressus forbesii Jeps.

Cupressus forbesii (Tecate cypress or Forbes' cypress)^[1] is a species of cypress in western North America. ^[2]

Distribution

Cupressus forbesii is native to chaparral and woodlands habitats and grows at 450–1,500 metres (1,480–4,900 ft). ^[2] It found in the western Peninsular Ranges in: Orange and San Diego Counties in Southern California; and northern Baja California, Mexico. ^[2]

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.

Description

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. ^[2]

Cupressus forbesii - Tecate Cypress bark,
at Guatay Mountain, Cuyamaca Mountains.

Taxonomy

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 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.

Ecology

The Tecate Cypress is the only plant on which the rare Thorne's Hairstreak (Callophrys gryneus thornei) lays its eggs.^[3]

Cultivation

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.

See also

• California chaparral and woodlands - (ecoregion)
• California montane chaparral and woodlands- (subecoregion)

Notes

1. ^ conifers.org: Cupressus forbesii. Accessed 12 November 2010.
2. ^ ^{a b c d} Jepson Manual
3. ^ Lee, M. Rare Otay butterfly doesn't make 'endangered' list. San Diego Union-Tribune February 22, 2011.

References

• 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.

External links

• Jepson Manual treatment for Cupressus forbesii
• The Gymnosperm Database: Cupressus forbesii
• USDA Profile for Cupressus forbesii (Tecate cypress)
• Cupressus forbesii - Photo Gallery