# Cupressus stephensonii
*Cupressus stephensonii* C.B.Wolf, commonly known as the Cuyamaca cypress, is a rare cypress tree native to the Cuyamaca Mountains of southwestern California, now usually placed in the genus *Hesperocyparis* as *Hesperocyparis stephensonii* (C.B.Wolf) Bartel.[1](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=48932) • [2](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A60451562-2) It is one of the most restricted cypresses in North America, known from a small area of San Diego County, and NatureServe assigns it the rank GX, Presumed Extinct, for its global status.[3](https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.135758/Hesperocyparis_stephensonii)
| Key fact | Detail |
|---|---|
| Accepted name | *Hesperocyparis stephensonii* (C.B.Wolf) Bartel, Phytologia 91(1): 183 (2009); basionym *Cupressus stephensonii* C.B.Wolf, Aliso 1: 125 (1948)[1](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=48932) • [4](https://www.ipni.org/n/72702-2) |
| Common name | Cuyamaca cypress[3](https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.135758/Hesperocyparis_stephensonii) |
| Native range | SW. California, Cuyamaca Mountains, San Diego County; a tree of the subtropical biome[2](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A60451562-2) |
| Size and bark | 10 to 16 m tall, trunk up to 7 dm in diameter, with thin, cherry-red, smooth, exfoliating bark[5](https://www.cupressus.net/CUstephensoniiWolf.html) |
| Foliage | Glaucous blue-gray or gray-green, turning greener after rains; a distinctive, somewhat lemon-like odor when lightly crushed[5](https://www.cupressus.net/CUstephensoniiWolf.html) |
| Conservation rank | NatureServe GX, Presumed Extinct[3](https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.135758/Hesperocyparis_stephensonii) |
| Fire adaptation | Serotinous cones; populations require several decades to accumulate cone banks and reproduce copiously after stand-replacement wildfire[6](https://escholarship.org/content/qt3r83g614/qt3r83g614_noSplash_89de85a38f7574231052f4cb50a77adc.pdf?t=mhwc5h) |
## Description
Carl B. Wolf's original 1948 description in *El Aliso* characterizes an erect or somewhat spreading tree 10 to 16 m in height, the broadest nearly 10 m in spread, generally with a straight central leader and a trunk up to 7 dm in diameter. The bark is thin, cherry-red, smooth and exfoliating, not at all fibrous, though older surfaces can be a bit grayish. The trees appear glaucous blue-gray or gray-green, with foliage definitely greener on new growth or after rains, and when lightly crushed it has a distinctive, somewhat lemon-like odor.[5](https://www.cupressus.net/CUstephensoniiWolf.html)
**Leaves and cones.** The leaves are about 1 mm long and wide, acutely pointed, rounded on the back, and usually develop an active dorsal pit; their ciliate or fimbriate margins are plainly visible under a low-power lens. Staminate cones are 2 to 4 mm long with 8 to 14 scales and 3 to 5 pollen sacs per scale. Seed cones reach about 10 mm diameter in the first season and up to about 25 mm at maturity, dull gray or brown with a somewhat roughened surface, and carry 100 to about 125 very dark brown seeds each, over 5 mm long with a broad thin wing.[5](https://www.cupressus.net/CUstephensoniiWolf.html) Seedlings have 3 or 4 cotyledons 10 to 13 mm long.[5](https://www.cupressus.net/CUstephensoniiWolf.html)
## Taxonomy
The species was described by Carl B. Wolf in *Aliso* 1: 125, published 10 April 1948, from a type collection (C. B. Wolf 9467) made on 1 December 1938 on the upper limits of King Creek in the Cuyamaca Mountains, at about 4,000 ft elevation, with the holotype held at RSA.[4](https://www.ipni.org/n/72702-2) Wolf named it in honor of Ranger Bert Stephenson of the [United States Forest Service](https://www.edgepedia.org/united-states-forest-service), long the District Ranger at Descanso in San Diego County, who died in 1944 and had noted the cypress trees on King Creek while fighting a forest fire there.[5](https://www.cupressus.net/CUstephensoniiWolf.html)
**Shifting genus placement.** The name has moved repeatedly. Little reduced it to *[Cupressus arizonica](https://www.edgepedia.org/cupressus-arizonica)* var. *stephensonii* in 1966, Murray treated it as a subspecies in 1982, and Little in 2006 transferred all [Western Hemisphere](https://www.edgepedia.org/western-hemisphere) *Cupressus* to the genus *Callitropsis*, making the combination *Callitropsis stephensonii*. Adams, Bartel, and Price in 2009 isolated the Western Hemisphere cypress lineage into a new genus, *Hesperocyparis*, producing the current combination.[3](https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.135758/Hesperocyparis_stephensonii) Little (2006), Adams et al. (2009), and Baldwin et al. (2012) treat it as a genetically distinct species of the Cuyamaca Mountains, while the *Flora of North America* includes it in the synonymy of *C. arizonica*.[3](https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.135758/Hesperocyparis_stephensonii) Kew's Plants of the World Online accepts *Hesperocyparis stephensonii* and lists four homotypic synonyms, while noting that Govaerts (2011) cited it as *Cupressus arizonica* var. *stephensonii*.[2](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A60451562-2)
## Relationships
When the species was first discovered it was thought to be just another locality for *C. forbesii*, a grove of which grows on Guatay Mountain only 7 or 8 miles away, but the harsh foliage and active glands place it with *C. arizonica* and *C. glabra* instead. Wolf judged *C. stephensonii* somewhat intermediate between those two species: it resembles *C. glabra* in its smooth, exfoliating bark but has much less glandular leaves, in which it resembles *C. arizonica*.[5](https://www.cupressus.net/CUstephensoniiWolf.html) The horticultural account in Bean (1976), now carried on Trees and Shrubs Online under the modern name, likewise describes it as allied to *Hesperocyparis glabra* but less glandular and with smaller leaves, about 1/25 inch long.[7](https://www.treesandshrubsonline.org/articles/hesperocyparis/hesperocyparis-stephensonii/)
## Distribution and rarity
The species is confined to a small area in [San Diego County, California](https://www.edgepedia.org/san-diego-county-california).[7](https://www.treesandshrubsonline.org/articles/hesperocyparis/hesperocyparis-stephensonii/) Peattie (1950) described it as known only from a few scattered trees on the headwaters of King Creek on the southwest side of Cuyamaca Peak, San Diego County.[8](https://www.conifers.org/~conifers/cu/Hesperocyparis_stephensonii.php) The type locality stands on a dry ridge near the creek in a mixed stand of *Adenostoma fasciculatum* var. *obtusifolium* and scattered *Pinus coulteri*, at the upper limits of the Upper Sonoran Life Zone or the lower limits of the Arid Transition Life Zone.[5](https://www.cupressus.net/CUstephensoniiWolf.html) The U.S. Fish and Wildlife Service maintains a species profile for the Cuyamaca cypress under the name *Callitropsis stephensonii* (TSN 822587).[9](https://www.fws.gov/species/cuyamaca-cypress-callitropsis-stephensonii)
## Fire ecology
**Serotiny and wildfire.** Like several other California cypresses, the Cuyamaca cypress is serotinous, holding closed cones on the tree for years, and a study of its recruitment after a stand-replacement wildfire describes an isolated population that, following drought, copiously reproduced after fire.[6](https://escholarship.org/content/qt3r83g614/qt3r83g614_noSplash_89de85a38f7574231052f4cb50a77adc.pdf?t=mhwc5h) Federal fire-management guidance notes that Cuyamaca cypresses require several decades to accumulate cone banks, so the interval between fires shapes whether a burned stand can regenerate.[10](https://downloads.regulations.gov/FWS-R8-ES-2017-0053-0007/attachment_17.pdf) This life history ties the species' persistence to fire return intervals long enough for cone banks to rebuild.
## References
1. [Hesperocyparis stephensonii, NCBI Taxonomy Browser](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=48932)
2. [Hesperocyparis stephensonii (C.B.Wolf) Bartel, Plants of the World Online, Kew](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A60451562-2)
3. [Hesperocyparis stephensonii, NatureServe Explorer](https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.135758/Hesperocyparis_stephensonii)
4. [Cupressus stephensonii C.B.Wolf, International Plant Names Index](https://www.ipni.org/n/72702-2)
5. [Cupressus stephensonii, original description by Carl B. Wolf (1948), Cupressus Conservation Project](https://www.cupressus.net/CUstephensoniiWolf.html)
6. [Recruitment patterns of an isolated serotinous conifer (Cupressus arizonica var. stephensonii) after stand-replacement wildfire, eScholarship](https://escholarship.org/content/qt3r83g614/qt3r83g614_noSplash_89de85a38f7574231052f4cb50a77adc.pdf?t=mhwc5h)
7. [Hesperocyparis stephensonii, Trees and Shrubs Online](https://www.treesandshrubsonline.org/articles/hesperocyparis/hesperocyparis-stephensonii/)
8. [Hesperocyparis stephensonii (Cuyamaca cypress) description, The Gymnosperm Database](https://www.conifers.org/~conifers/cu/Hesperocyparis_stephensonii.php)
9. [Cuyamaca Cypress (Callitropsis stephensonii), U.S. Fish & Wildlife Service](https://www.fws.gov/species/cuyamaca-cypress-callitropsis-stephensonii)
10. [Fire management life-history attributes, U.S. Fish and Wildlife Service document](https://downloads.regulations.gov/FWS-R8-ES-2017-0053-0007/attachment_17.pdf)
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*Topic: Encyclopedia › Life and health › Plants and algae › Seed plants › Conifers and other gymnosperms › Conifers › Cupressaceae — cypresses, junipers, cedars, and redwoods › Cypresses (Cupressus and allies) › New World cypresses (Hesperocyparis and American relatives)*
*Initially written Sep 17, 2026 · Reviewed: Oct 21, 2026 · Edited: Oct 15, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license