''Cupressus arizonica'', the Arizona cypress, is a North American species of tree in the cypress family Cupressaceae, native to the southwestern United States and Mexico. Populations may be scattered rather than in large, dense stands.

Description

''Cupressus arizonica'' is a

conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single ...

ous evergreen tree with a conic to ovoid-conic crown. It grows to heights of , and its trunk diameter reaches . The foliage grows in dense sprays, varying from dull gray-green to bright

glaucous ''Glaucous'' (, ) is used to describe the pale grey or bluish-green appearance of the surfaces of some plants, as well as in the names of birds, such as the glaucous gull (''Larus hyperboreus''), glaucous-winged gull (''Larus glaucescens''), g ...

blue-green. The leaves are scale-like, 2–5 mm long, and produced on rounded (not flattened) shoots. The seed cones are globose to oblong, 15–33 mm long, with 6 or 8 (rarely 4 or 10) scales, green at first, maturing gray or gray-brown about 20–24 months after pollination. The cones remain closed for many years, only opening after the bearing branch is killed (in a wildfire or otherwise), allowing the seeds to colonize the bare ground exposed by the fire. The male cones are 3–5 mm long, and release pollen in February–March.

Taxonomy

Up to five varieties are distinguished by some botanists, and these are sometimes treated as distinct species: * ''Cupressus arizonica'' var. ''arizonica'', Arizona Cypress – secure. Southern Arizona, southwest New Mexico, south to Durango and Tamaulipas, Chisos Mountains of west Texas. * ''Cupressus arizonica'' var. ''glabra'', Smooth Arizona cypress – secure. Central Arizona. * ''Cupressus arizonica'' var. ''montana'' (''C. montana''), San Pedro Mártir cypress – Vulnerable. Sierra Juárez and San Pedro Mártir pine–oak forests of Northern Baja California. * ''Cupressus arizonica'' var. ''nevadensis'' (''C. nevadensis''), Paiute cypress – Least Concern. Southern California ( Kern County and Tulare County). * ''Cupressus arizonica'' var. ''stephensonii'', Cuyamaca cypress – Critically endangered. Southern California ( San Diego County). Also known as ''Hesperocyparis stephensonii'' (Jespon Manual). Most of this population was burnt in the October 2003 Cedar Fire, though (as expected for a fire-climax species) subsequent regeneration has been good.

Distribution

''Cupressus arizonica'' is found mainly in the southwestern United States ( Arizona, Utah, southwestern New Mexico, and southern California, with a few populations in southern Nevada and in the Chisos Mountains of western Texas), and in Mexico (

Coahuila Coahuila (), formally Coahuila de Zaragoza (), officially the Free and Sovereign State of Coahuila de Zaragoza ( es, Estado Libre y Soberano de Coahuila de Zaragoza), is one of the 32 states of Mexico. Coahuila borders the Mexican states of N ...

Nuevo León Nuevo León () is a state in the northeast region of Mexico. The state was named after the New Kingdom of León, an administrative territory from the Viceroyalty of New Spain, itself was named after the historic Spanish Kingdom of León. With a ...

Chihuahua Chihuahua may refer to: Places *Chihuahua (state), a Mexican state **Chihuahua (dog), a breed of dog named after the state **Chihuahua cheese, a type of cheese originating in the state **Chihuahua City, the capital city of the state **Chihuahua Mun ...

Sonora Sonora (), officially Estado Libre y Soberano de Sonora ( en, Free and Sovereign State of Sonora), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is d ...

Durango Durango (), officially named Estado Libre y Soberano de Durango ( en, Free and Sovereign State of Durango; Tepehuán: ''Korian''; Nahuatl: ''Tepēhuahcān''), is one of the 31 states which make up the 32 Federal Entities of Mexico, situated in ...

, Tamaulipas, Zacatecas and northern Baja California). In the wild, the species is often found in small, scattered populations, not necessarily in large forests. An example occurrence is within the Sierra Juárez and San Pedro Mártir pine–oak forests of Mexico, where it is found along with canyon live oak and California fan palm.

Uses

Arizona cypress, particularly the strongly

''C. arizonica''

var. In botanical nomenclature, variety (abbreviated var.; in la, varietas) is a taxonomic rank below that of species and subspecies, but above that of form. As such, it gets a three-part infraspecific name. It is sometimes recommended that the ...

''glabra'', is widely cultivated as an ornamental tree. Unlike Monterey cypress, it has proved highly resistant to cypress canker, caused by the fungus '' Seiridium cardinale'', and growth is reliable where this disease is prevalent. The cultivar 'Pyramidalis' has gained the Royal Horticultural Society's

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

(confirmed 2017).

Example of neoendemism and conservation challenges

The ease of

hybridization Hybridization (or hybridisation) may refer to: *Hybridization (biology), the process of combining different varieties of organisms to create a hybrid *Orbital hybridization, in chemistry, the mixing of atomic orbitals into new hybrid orbitals *Nu ...

cypress Cypress is a common name for various coniferous trees or shrubs of northern temperate regions that belong to the family Cupressaceae. The word ''cypress'' is derived from Old French ''cipres'', which was imported from Latin ''cypressus'', the ...

species in the American southwest has fostered a parallel history of

taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

disagreements of where genus and species distinctions should apply. It thus provides a case study of neoendemism in conifers. Close taxonomic relatedness, in turn, offers both challenges and opportunities if and when assisted migration is considered as a mode of climate adaptation to prevent extinctions of endemic cypresses in the American southwest.

References

External links

USDA Plants Profile for ''Hesperocyparis arizonica'' (Arizona cypress)
* as ''Hesperocyparis stephensonii'' * as ''Hesperocyparis stephensonii''
Hike Arizona.com: Photos of Arizona Cypress (''Cupressus arizonica'')
* {{Taxonbar, from=Q670040 arizonica Flora of Arizona Flora of California Flora of New Mexico Trees of Coahuila Trees of Chihuahua (state) Trees of Sonora Trees of Durango Trees of Tamaulipas Trees of Zacatecas Trees of Baja California Flora of Texas Trees of the South-Central United States Trees of the Southwestern United States Natural history of the Transverse Ranges Plants described in 1882 Taxa named by Edward Lee Greene Least concern flora of North America