- Cupressus stephensonii
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Cupressus stephensonii 
Conservation status Scientific classification Kingdom: Plantae Division: Pinophyta Class: Pinopsida Order: Pinales Family: Cupressaceae Genus: Cupressus Species: C. stephensonii Binomial name Cupressus stephensonii
C.B.WolfSynonyms 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]
Contents
Distribution
The Cuyamaca Cypress exists only in the headwaters area of King Creek in the Peninsular Ranges, 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.[8][3]
Cupressus stephensonii trunk -
-note the very subtle differences in bark color and texture from Cupressus glabra and Cupressus forbesiiTaxonomy 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
- Cupressus forbesii - nearby endemic cypress sp.
References
- ^ California Native Plant Society Rare Plant Profile
- ^ http://ucjeps.berkeley.edu/cgi-bin/get_cpn.pl?50023 Jepson -C. a. subsp s.
- ^ a b c d http://ucjeps.berkeley.edu/cgi-bin/get_cpn.pl?21406 . accessed 11.11.2010 Jepson- (C. B. Wolf) Bartel.-Hesperocyparis
- ^ Wolf
- ^ a b http://www.conifers.org/cu/cup/stephensonii.htm conifers.org
- ^ http://www.fs.fed.us/psw/programs/rna/king_creek.shtml
- ^ IUCN Red List
- ^ Lanner, R. 1999. Conifers of California. Cuchama Press. (274 p.)
- Wolf, C. B. & Wagener, W. E. (1948). The New World Cypresses. El Aliso 1: 195-205.
- palomar.edu: The True Cypresses (Genus Cupressus = Callitropsis) "Isolated Groves In Western North America" - (web.article)
External links
Categories:- IUCN Red List vulnerable species
- Cupressus
- Endemic flora of California
- Trees of California
- Flora of California chaparral and woodlands
- Plants described in 1948
- Natural history of San Diego County, California
- Vulnerable flora of California
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