C. Michael Hogan and Michael P. Frankis
January 27, 2009
The Monterey Cypress is a magnificent twisted coastal tree endemic to a highly restricted locus in central California. It is often used as an iconic representation to symbolize the natural setting of the Monterey Peninsula and coastline south of Carmel Valley. This threatened species is associated with highly specialized acidic soils, and its forests also foster a high degree of endemism with flora associates.
Monterey Cypress has only two occurrences, both in coastal Monterey County, California, USA (Griffin & Critchfield 1976, Farjon et al. 1999). These two disjunct stands are found at Point Lobos and at Cypress Point in the Del Monte Forest, separated by about five kilometers across Carmel Bay. Both stands are situated on the coast at elevations less than 30 meters, and are considered relicts of a wider historical distribution. Schoenherr refers to these isolated stands as relict "ecologic islands" (Schoenherr 1995). Historically the presence of these stands was first noted in the year 1602 by explorer Sebastian Viscaino, the first European noting Point Lobos. The species is locally naturalized further north along the California and Oregon coast, and occasionally in New Zealand and the Atlantic coastal regions of Europe.
Currently the genus rank is being reviewed based upon molecular biology and genetic data, with the outcome that C. macrocapra and other New World cypresses are proposed by some botanists for transfer to a new genus Callitropsis, syn. Xanthocyparis (Little et al. 2004, Little 2006), though this is disputed by others (Xian & Li 2005, Mu et al. 2006, and the Cupressus Conservation Project) who support retention of Callitropsis within Cupressus.
The genus etymology is based on the Latin word derived from the Greek word "Kuparissos" (for C. sempervirens), and possibly related to the Hebrew word "gopher" (Frankis 1992). The species name refers to its cones, which are larger than those of most other cypresses.
Mature Monterey Cypress can achieve a height of 20 to 25 meters, and ages realized in both groves have been estimated to be as high as 200 to 300 years (Jepson 1993). The gnarled appearance of the tree's architecture and broad spreading crown give rise to an iconic shape on the Monterey Peninsula. There is sometimes a marked assymetry in exposed locations, presumably from caused by wind and salt pruning. The mature trunk bark is a rich brown scaly or fibrous composition, while the young twig shoots are approximately two mm in diameter and cylindric in shape. Leaf scales are bright green in coloration. The pollen cones are approximately six mm in length and about half that size in diameter; each pollen cone has 12 to 14 scales, with each scale exhibiting six to ten pollen sacs. The brown spherical to elliptic seed cone has a length of 2.5 to 3.8 cm (rarely 2 cm or up to 4 cm) with a diameter of 1.7 to 2.5 cm; there are eight to 12 (rarely 14) scales per seed cone. The dark brown seeds are up to six mm long, with a thickness of about half the length; attachment scars are a conspicuous white. Pollination is in early spring, with seed maturity about 18 to 24 months later. Cones of the related Gowen Cypress C. goveniana are usually smaller than those of Monterey Cypress, typically 1.5-2.5 cm long.
Both extant wild stands of C. macrocarpa occur on highly specialized soils consisting of thin mantles of moderately acidic soil overlying granitic bases. These two closed canopy stands are classified as fire-climax closed-cone pine/cypress forests, and are situated on coastal headlands with soils rich in organic matter. They are strictly confined to the summer-cool coastal fog belt where sea fog is frequent and dense. Nearby overstory vegetation includes C. goveniana var goveniana, although C. goveniana occurs within 1.5-2 km of C. macrocarpa, the two don't occur together at all. The co-dominant overstory species withing the two groves where C. macrocarpa occurs is primarily Pinus radiata. The Del Monte Forest is particularly rich in associated flora endemic to the California Central Coast or slightly expanded ranges and characterized by restricted distribution. Examples of these listed endemics include C. goveniana, Potentilla hickmanii, Astragalus tener var. titi, Piperia yadonii and Trifolium trichocalyx (Hogan et al. 1992).
On the rocky Pacific coastline of the two Monterey Cypress stands, there is frequently a transition to Northern coastal bluff scrub. Other species that are understory associates of C. macrocarpa include Artemisia californica, Archtostaphlos tomentosa, Ceanothus thyrsiflorus, Dudleya farinosa, Erigeron glaucus, Eriophyllum confertiflorum, E.staechidifolium, Iris douglasiana and Navarretia squarrosa.
Germination of new trees is solely from seed, with cone production being prolific. Staminate cone maturity occurs at approximately age six, while ovulate cones are produced on trees that are about ten years or older. C. macrocarpa cones stay closed for several years after maturity. Seed release is often assisted by forest fires, though not requiring it invariably. Seed dispersal is conducted chiefly by wind; dispersal distances are very small.
Young seedlings of C. macrocarpa are eaten by Black-tailed deer and a number of rodent species. Seedlings are also susceptible to damping-off fungi. Other pathogens infesting this tree include the fungal disease Seiridium cardinale (syn. Coryneum cardinale), whose attack may result in tree mortality. The bark beetle Ernobius conicola attacks both green and dry C. macrocarpa cones as well as dead branches of the tree. Larvae of two moths (Laspeyresia cupressana and Henricus macrocarpara) may harm the seeds.
Interaction with man
Significant human prehistory is associated with both extant C. macrocarpa stands. One can observe abalone shell dominant middens and grinding stones amongst the groves, indicating Rumsien and other Ohlone tribe habitation millennia earlier. In one of the Point Lobos middens the archaeological site is clearly situated at a locus protected by enormous boulder outcrops, and yet with a scenic ocean vista. I could observe clear evidence of fire darkened soil at this site (Hogan et al. 1992).
Monterey Cypress is a popular ornamental tree in mild areas, though when planted in climates with hot summers, including inland California away from the coastal fog belt, it is usually short-lived due to its susceptibility to Seiridium cardinale (Wagener 1948). Cultivated specimens can become much larger than the wild trees, with trees known up to 48 m tall in New Zealand and 42 m tall in Ireland.
Monterey Cypress is, with Nootka Cypress C. nootkatensis, one of the parents of the popular garden hybrid Leyland Cypress C. × leylandii.
* Schoenherr, A. A. (1995). A Natural History of California, University of California Press, 772 pages. ISBN 0520069226 http://books.google.com/books?id=hk66OIHoesEC
* Farjon, A., Page C. N., & Brown, M. J. (1999). Conifers: Status Survey and Conservation Action Plan. IUCN, 121 pages ISBN 2831704650
* Frankis, M. P. (1992). Cupressus. In: Griffiths et al., eds. The New RHS Dictionary of Gardening 1: 781-783
* Griffin, J. R. & Critchfield, W. B. (1976). The Distribution of Forest Trees in California. USDA Forest Service Research Paper PWS-82.
* Little, D. P. (2006). Evolution and circumscription of the true Cypresses. Systematic Botany 31 (3): 461-480.
* Little, D. P., Schwarzbach, A. E., Adams, R.P., & Hsieh, C.F. (2004). The circumscription and phylogenetic relationships of Callitropsis and the newly described genus Xanthocyparis (Cupressaceae). Amer. J. Bot. 91 (11): 1872-1881.
* Jepson Manual (1993). University of California Press, Berkeley, Ca.
* Hogan, C. M., Deghi, G., Papineau, M., et al. (1992) Environmental Impact Report for the Pebble Beach Properties project by Del Monte Forest, Earth Metrics Inc. Prepared for the city of Monterey and State of California Clearinghouse, Sacramento, Ca.
* Mu, L., Wang, L., Yao, L., Hao, B, & Luo, Q. (2006). Application of pet G-trn P sequence to systematic study of Chinese Cupressus species. Frontiers of Biology in China 4: 349-352.
* Wagener, W. E. (1948). Diseases of Cypresses. El Aliso 1: 253-321.
* Xiang, Q., & Li, J. (2005). Derivation of Xanthocyparis and Juniperus from within Cupressus: Evidence from Sequences of nrDNA Internal Transcribed Spacer Region. Harvard Papers in Botany 9 (2): 375-382.