Cupressus stephensonii

Cupressus stephensonii
Scientific classification
Kingdom: Plantae
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Cupressaceae
Genus: Cupressus
Species: C. stephensonii
Binomial name
Cupressus stephensonii
C.B.Wolf
Natural range of Cupressus stephensonii
Synonyms

Callitropsis stephensonii (C.B.Wolf) D.P.Little[1]

Cupressus stephensonii is a species of conifer known as the Cuyamaca cypress, and endemic to California. It is sometimes listed as Cupressus arizonica subsp. stephensonii,[2] and Hesperocyparis stephensonii [3]

Distribution

The Cuyamaca Cypress exists only in the headwaters area of King Creek in the Cuyamaca Mountains, south of Cuyamaca Peak within San Diego County in extreme Southern California.

Trees were reported growing as low as 3,000 feet (910 m) in elevation in 1998, but the presence of these individuals today has not been verified.[4] Most individual trees occur at 4,500–5,100 feet (1,400–1,600 m) within the King Creek Research Natural Area in the Cleveland National Forest.[5][6]

Conservation

It is listed as a vulnerable species.[7] However the last IUCN Red List assessment occurred in 1998, before the entire native (world) population of the tree here was reduced to thirty to forty individual trees by the 2003 Cedar Fire.

Description

Cupressus stephensonii may attain heights of 10 to 16 m (33 to 52 ft).[5] It usually forms a spreading tree with a central leader, only slightly taller than it is wide.

Female cones about 10 mm in diameter, cone scales 6-8, but mostly 6, often, but not always, with conspicuous umbos 3–4 mm high and conical. Seeds average 100-125 per cone, not at all glaucous. Cotyledons 3-4. It is the only California Cypress species to release pollen in the summertime.[3][8]

Cupressus stephensonii trunk -
-note the very subtle differences in bark color and texture from Cupressus glabra and Cupressus forbesii

Taxonomy variations

Cupressus stephensonii is sometimes listed as Cupressus arizonica subsp. stephensonii, as subspecies of Arizona cypress (Cupressus arizonica),[3] It can be hard to distinguish the two, one of the main distinguishing characteristics is the color of the smooth bark on mature trees which varies from pink to grey to pure white, as well as the mature form which tends to be much more spreading than C. arizonica. The listing of Cupressus stephensonii as a subspecies of Cupressus arizonica is debatable.

The more recent name Hesperocyparis stephensonii is also used by some botanists.[3] Further molecular analysis may help define the taxonomy.

See also


References

  1. ↑ California Native Plant Society Rare Plant Profile
  2. ↑ http://ucjeps.berkeley.edu/cgi-bin/get_cpn.pl?50023 Jepson -C. a. subsp s.
  3. 1 2 3 4 http://ucjeps.berkeley.edu/cgi-bin/get_cpn.pl?21406 . accessed 11.11.2010 Jepson- (C. B. Wolf) Bartel.-Hesperocyparis
  4. ↑ Wolf
  5. 1 2 http://www.conifers.org/cu/cup/stephensonii.htm conifers.org
  6. ↑ http://www.fs.fed.us/psw/programs/rna/king_creek.shtml
  7. ↑ IUCN Red List
  8. ↑ Lanner, R. 1999. Conifers of California. Cuchama Press. (274 p.)

Further reading

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