Index of Species Information

SPECIES:  Hesperocyparis macnabiana


SPECIES: Hesperocyparis macnabiana
AUTHORSHIP AND CITATION : Esser, Lora L. 1994 Hesperocyparis macnabiana. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: []. Revisions: 17 October 2013: Scientific name changed from Cupressus macnabiana to Hesperocyparis macnabiana; references 28-31 added. ABBREVIATION : HESMAN SYNONYMS : Callitropsis macnabiana (A. Murray bis) D.P. Little [31] Cupressus macnabiana Murr. [14,18,24,28] Neocupressus macnabiana (A. Murray bis) de Laub. [29] NRCS PLANT CODE : HEMA21 COMMON NAMES : MacNab cypress TAXONOMY : The currently accepted scientific name of MacNab cypress is Hesperocyparis macnabiana (A. Murray bis) Bartel [23,28]. There are no recognized infrataxa. Natural hybridization between MacNab cypress and Sargent cypress (H. sargentii) has been hypothesized, but evidence for it is inconclusive [13,17,27]. LIFE FORM : Tree FEDERAL LEGAL STATUS : No special status OTHER STATUS : NO-ENTRY


SPECIES: Hesperocyparis macnabiana
GENERAL DISTRIBUTION : MacNab cypress occurs only in California and has the widest distribution of any of the California cypress [14,27]. Numerous scattered groves occur in the inner North Coast Ranges, the Sierra Nevada foothills, and the Cascade Range [14,24,27]. Over 30 groves occur in the following counties: Sonoma, Napa, Yolo, Mendocino, Lake, Colusa, Tehama, Shasta, Butte, Nevada, Yuba, and Amador [27]. ECOSYSTEMS : FRES20 Douglas-fir FRES21 Ponderosa pine FRES27 Redwood FRES28 Western hardwoods FRES34 Chaparral - mountain shrub STATES : CA BLM PHYSIOGRAPHIC REGIONS : 3 Southern Pacific Border 4 Sierra Mountains KUCHLER PLANT ASSOCIATIONS : K005 Mixed conifer forest K006 Redwood forest K029 California mixed evergreen forest K030 California oakwoods K033 Chaparral SAF COVER TYPES : 229 Pacific Douglas-fir 232 Redwood 233 Oregon white oak 244 Pacific ponderosa pine - Douglas-fir 245 Pacific ponderosa pine 247 Jeffrey pine 248 Knobcone pine SRM (RANGELAND) COVER TYPES : NO-ENTRY HABITAT TYPES AND PLANT COMMUNITIES : MacNab cypress is a component of the northern interior cypress forest. This community is an open, fire-maintained, scrubby forest similar to the knobcone pine (Pinus attenuata) forest. It is associated with serpentine chaparral, and intergrades on less severe sites with upper Sonoran mixed chaparral, montane chaparral, or knobcone pine forest community types. On more mesic sites the northern interior cypress forest intergrades with mixed evergreen forest or montane coniferous forest [11]. MacNab cypress is associated with redwood (Sequoia sempervirens)-Douglas-fir (Pseudotsuga menziesii) forest and associated North Coast forests in Mendocino County, California [6,26]. It is also commonly associated with chaparral and pine-oak (Pinus-Quercus spp.) woodland species [8,27]. The Magalia grove in Butte County is surrounded by yellow pine forest (Pinus ponderosa and P. jeffreyi) [27]. MacNab cypress occurs sympatrically with Sargent cypress in Lake County, California [16]. Publications naming MacNab cypress as a community dominant are listed below. Terrestrial natural communities of California [9] Terrestrial vegetation of California [27] Species not previously mentioned but commonly associated with MacNab cypress include gray pine (Pinus sabiniana), sugar pine (P. lambertiana), incense-cedar (Libocedrus decurrens), California scrub oak (Quercus dumosa), leather oak (Q. durata), interior live oak (Q. wislizenii), valley oak (Q. lobata), Sierra coffeeberry (Rhamnus rubra), California coffeeberry (R. californica), yerba santa (Eriodictyon californicum), chaparral pea (Pickeringia montana), golden-fleece (Haplopappus arborescens), Garrya congdonii (interior silktassel), California hop tree (Ptelea crenulata), chamise (Adenostoma fasciculatum), wedgeleaf ceanothus (Ceanothus cuneatus), musk brush (C. jepsonii), whiteleaf manzanita (Arctostaphylos viscida), creeping sage (Salvia sonomensis), and styrax (Styrax officinalis var. californica) [6,24,26,27].


SPECIES: Hesperocyparis macnabiana
WOOD PRODUCTS VALUE : MacNab cypress has soft, close-grained wood [24]. Cypress (Hesperocyparis spp.) wood is generally durable and stable. It is suitable for a wide range of exterior uses including joinery, shingles, and boats. Possible interior uses include moulding and panelling [17]. Cypress shelterbelts provide good fuel. Most cypress species develop a large proportion of heartwood, which splits well, dries quickly, and is clean-burning. Cypress wood is moderately fast burning because of its medium density. As cypress woods are prone to sparking, they are recommended only for enclosed fires [17]. IMPORTANCE TO LIVESTOCK AND WILDLIFE : Rodents and deer consume cypress seedlings. Cypress are considered undesirable forage for livestock, although young plants are browsed [24]. PALATABILITY : NO-ENTRY NUTRITIONAL VALUE : NO-ENTRY COVER VALUE : NO-ENTRY VALUE FOR REHABILITATION OF DISTURBED SITES : NO-ENTRY OTHER USES AND VALUES : NO-ENTRY OTHER MANAGEMENT CONSIDERATIONS : Grazing and trampling by livestock are detrimental to cypress seedlings [1]. MacNab cypress is unsuitable for use in windbreaks or hedges near the coast or in areas that are waterlogged, because waterlogged soils may result in dwarfed trees [24,27]. Seedlings are susceptible to damping-off fungi [27]. MacNab cypress is moderately susceptible to coryneum canker (Coryneum cardinale), which can kill trees [24]. It succumbs to various diseases when transplanted from warm, dry interior locations to the cool, moist atmosphere of the coast [24]. MacNab cypress is restricted to serpentine soils in many locations. Using cypress wood to fuel the furnaces used to extract mercury from sepentine soils has reduced California's cypress forests [1].


SPECIES: Hesperocyparis macnabiana
GENERAL BOTANICAL CHARACTERISTICS : MacNab cypress is a native, evergreen tree with a broad crown and lacking a main trunk [10,24]. It grows from 9.9 to 33 feet (3-10 m) tall [8]. It is unique among North American cypress because of the flat, sprayed arrangement of its branches [2,24]. Mature leaves are generally about 0.06 inch (1.5 mm) long, although they can be up to 0.4 inch (10 mm) on vigorous shoots [8,24]. Ovulate cones are solitary, up to 1.0 inch (25 mm) long. Staminate cones are 0.08 to 0.12 inch (2-3 mm) long [8,24]. The bark is furrowed and fibrous, 2.54 to 5.1 inches (1-2 cm) thick, and not exfoliating [24]. A well-defined taproot and numerous laterals are formed the first year [10]. RAUNKIAER LIFE FORM : Phanerophyte REGENERATION PROCESSES : MacNab cypress reproduces exclusively from seed. Cone production is abundant. Staminate cones are produced on trees that are 6 to 7 years old [24]. Ovulate cones are produced on trees that are 14 years of age or older. The cones require 2 years to mature [2]. They contain from 75 to 105 seeds each [10,24]. The cones are closed; they persist on the tree until opened by the heat of a fire or from desiccation due to age [10,27]. Seeds are shed gradually over several months after the cones are opened [27]. Detached cones will open, but they rarely result in seedling establishment, usually due to the lack of a suitable seedbed [2]. Seed dispersal is primarily by wind and rain [27]. MacNab cypress germination rates are extremely low, less than 5 percent [16]. Seeds require bare mineral soil for germination and establishment. Seedling mortality is greater on shaded sites with abundant litter because of damping-off fungi [2,27]. Seedlings are sensitive to excessive moisture [24]. SITE CHARACTERISTICS : In many areas MacNab cypress is restricted to serpentine soils, but in other locations it occurs on clay loam (up to 5.0 feet [1.5 m] deep), silty loam, alluvial, granitic, and volcanic soils [13,16,27]. It is found on dry slopes, exposed hillsides, and ridgetops [8,16,20]. It occurs at elevations from 1,000 to 2,800 feet (300-850 m) on north- to northeast-facing slopes [8,20]. SUCCESSIONAL STATUS : Site requirements for cypress seedlings are typical of those for pioneer conifers. Seedlings are shade intolerant and survive best in full sunlight on bare mineral soil [27]. Perhaps due to its shorter, bushier habit, MacNab cypress is found on more exposed sites than Sargent cypress where the two species occur together [16]. SEASONAL DEVELOPMENT : MacNab cypress starts shedding its pollen around October 28 [24]. Seeds mature 15 to 18 months after pollination. Ovulate cones remain closed until opened by heat or age [10,24].


SPECIES: Hesperocyparis macnabiana
FIRE ECOLOGY OR ADAPTATIONS : MacNab cypress is a fire-adapted, fire-dependent species. Successful cypress (Hesperocyparis spp.) reproduction is generally restricted to burned sites [27]. The serotinous cones persist on the trees for years [25]. Cone opening is erratic, slow, and almost negligible except when cones are exposed to extreme heat; then it is rapid and uniform [25]. When opened by the heat of a fire, the seeds fall on exposed mineral soil [14,24]. Most seed falls in the first few months following fire [25]. Fires that occur in late summer and fall and are followed by winter rains ensure seed dissemination on bare mineral substrates [27]. No information was available on fire-free intervals for communities dominated by MacNab cypress. However, Tecate cypress (Hesperocyparis forbesii), a cypress found in southern California, has an average interval between fires of 25 years, ranging from 15 to 63 years [2]. Cypress trees of southern California generally reach cone-bearing age before another fire occurs [27]. POSTFIRE REGENERATION STRATEGY : Tree without adventitious-bud root crown Crown residual colonizer (on-site, initial community) Initial-offsite colonizer (off-site, initial community)


SPECIES: Hesperocyparis macnabiana
IMMEDIATE FIRE EFFECT ON PLANT : Most fires probably kill MacNab cypress. Cypress thickets are conducive to crown fires, which usually kill almost all trees in the stand [27]. At the Rancho Santa Ana Botanic Garden in southern California on October 8, 1943, a severe fire killed all but three MacNab cypress trees [24]. Cones of the California cypress open as the resin melts and boils. Rapid charring of the thick cone scales extinguishes the flames, leaving seeds unburned [2]. DISCUSSION AND QUALIFICATION OF FIRE EFFECT : NO-ENTRY PLANT RESPONSE TO FIRE : MacNab cypress release large quantities of seed after fire [24]. In Lake County, it occurs on recently burned areas with Sargent cypress [16]. In Aukum, California, many decadent MacNab cypress were reported in 1948. The prevalence of "overmature and decadent" Macnab cypress trees was attributed to the absence of fire, which was veiwed as unusual for this species. A few miles south, in Hooker Canyon, Sonoma County, a chaparral atand of chamise and California scrub oak contained a few old MacNab cypress, numerous burned MacNab cypress stumps, and many young MacNab cypress trees [24]. Seedling regeneration is not as extensive for MacNab cypress as for other cypress species, possible due to low germination rates [24]. DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : NO-ENTRY FIRE MANAGEMENT CONSIDERATIONS : Fires occurring too frequently in McNab cypress groves may destroy them, as reproduction could be eliminated before it had a chance to produce cones. Conversely, fire suppression could threaten the species.


SPECIES: Hesperocyparis macnabiana
REFERENCES : 1. Airola, Daniell A.; Messick, Timothy C. 1987. Sliding toward extinction: the state of California's natural heritage, 1987. Report prepared at the request of the California Senate Committee on Natural Resources and Wildlife. [Location of publisher unknown]: [Publisher unknown]. 123 p. On file at: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT. [19482] 2. Armstrong, Wayne P. 1966. Ecological and taxonomic relationships of Cupressus in southern California. Los Angles, CA: California State College. 129 p. Thesis. [21332] 3. Bannan, M. W. 1954. The wood structure of some Arizonan and Californian species of Cupressus. Canadian Journal of Botany. 32: 285-307. [20691] 4. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. [434] 5. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905] 6. Gardner, Robert A. 1958. Soil-vegetation associations in the redwood - Douglas-fir zone of California. In: Proceedings, 1st North American forest soils conference; [Date of conference unknown]; East Lansing, MI. East Lansing, MI: Michigan State University, Agricultural Experiment Station: 86-101. [12581] 7. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998] 8. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. Berkeley, CA: University of California Press. 1400 p. [21992] 9. Holland, Robert F. 1986. Preliminary descriptions of the terrestrial natural communities of California. Sacramento, CA: California Department of Fish and Game. 156 p. [12756] 10. Johnson, LeRoy C. 1974. Cupressus L. cypress. In: Schopmeyer, C. S., technical coordinator. Seeds of woody plants in the United States. Agric. Handb. 450. Washington, DC: U.S. Department of Agriculture, Forest Service: 363-369. [7599] 11. Kruckeberg, Arthur R. 1984. California serpentines: flora, vegetation, geology, soils and management problems. Publications in Botany Volume 48. Berkeley, CA: University of California Press. 180 p. [12482] 12. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384] 13. Lawrence, Lorraine; Bartschot, Rita; Zavarin, Eugene; Griffin, James R. 1975. Natural hybridization of Cupressus sargentii and C. macnabiana and the composition of the derived essential oils. Biochemical Systematics and Ecology. 2(11): 113-119. [22055] 14. Little, Elbert L., Jr. 1975. Rare and local conifers in the United States. Conservation Research Rep. No. 19. Washington, DC: U.S. Department of Agriculture, Forest Service. 25 p. [15691] 15. Little, Elbert L., Jr. 1979. Checklist of United States trees (native and naturalized). Agric. Handb. 541. Washington, DC: U.S. Department of Agriculture, Forest Service. 375 p. [2952] 16. McMillan, Calvin. 1956. The edaphic restriction of Cupressus and Pinus in the Coast Ranges of central California. Ecological Monographs. 26: 177-212. [11884] 17. Miller, J. T.; Knowles, F. B. 1990. Introduced forest trees in New Zealand: recognition, role and seed source. 9. The cypresses: Cupressus spp. and Chamaecyparis spp. FRI Bulletin 124/9. Christchurch, New Zealand: New Zealand Forest Service. 33 p. [21880] 18. Mitchell, Alan F. 1972. Conifers in the British Isles: A descriptive handbook. Forestry Commission Booklet No. 33. London: Her Majesty's Stationery Office. 322 p. [20571] 19. Munz, Philip A. 1973. A California flora and supplement. Berkeley, CA: University of California Press. 1905 p. [6155] 20. Posey, Clayton E.; Goggans, James F. 1967. Observations on species of cypress indigenous to the United States. Circular 153. Auburn, AL: Auburn University, Agricultural Experiment Station. 19 p. [20384] 21. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843] 22. Stickney, Peter F. 1989. Seral origin of species originating in northern Rocky Mountain forests. Unpublished draft on file at: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT; RWU 4403 files. 7 p. [20090] 23. U.S. Department of Agriculture, Natural Resources Conservation Service. 2013. PLANTS Database, [Online]. Available: [34262] 24. Wolf, Carl B.; Wagener, Willis W. 1948. The New World cypresses. El Aliso Series: Vol. 1. Anaheim, CA: Rancho Santa Ana Botanic Garden. 444 p. [20740] 25. Zedler, Paul H. 1986. Closed-cone conifers of the chaparral. Fremontia. 14(3): 14-17. [18648] 26. Zinke, Paul J. 1977. The redwood forest and associated north coast forests. In: Barbour, Michael G.; Major, Jack, eds. Terrestrial vegetation of California. New York: John Wiley and Sons: 679-698. [7212] 27. Vogl, Richard J.; Armstrong, Wayne P.; White, Keith L.; Cole, Kenneth L. 1977. The closed-cone pines and cypress. In: Barbour, Michael G.; Major, Jack, eds. Terrestrial vegetation of California. New York: John Wiley and Sons: 295-358. [7219] 28. Baldwin, Bruce G.; Goldman, Douglas H.; Keil, David J.; Patterson, Robert; Rosatti, Thomas J.; Wilken, Dieter H., eds. 2012. The Jepson manual. Vascular plants of California, second edition. Berkeley, CA: University of California Press. 1568 p. [86254] 29. de Laubenfels, D. J. 2009. Nomenclatural actions for the New World cypresses (Cupressaceae). Novon: A Journal for Botanical Nomenclature. 19(3): 300-306. [87295] 30. Flora of North America Editorial Committee, eds. 2013. Flora of North America north of Mexico, [Online]. Flora of North America Association (Producer). Available: [36990] 31. Little, Damon P. 2006. Evolution and circumscription of the true cypresses (Cupressaceae: Cupressus). Systematic Botany. 31(3): 461-480. [87294]

FEIS Home Page