The Gymnosperm Database

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Foliage, pollen cones and seed cones of a tree in habitat [Tim Ives ©2002].

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Tree, Ash Creek grove [Tim Ives ©2002].

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The largest known specimen [Frank Callahan 2010].

 

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Conservation status 2013

Hesperocyparis macnabiana

(A.Murray bis) Bartel 2009

Common names

McNab cypress.

Taxonomic notes

Synonymy: see POWO (accessed 2023.12.16). "In the inner north Coast Ranges H. macnabiana and H. sargentii produce the only known natural hybrids in Hesperocyparis (Lawrence et al. 1975)" (Eckenwalder 1993).

Description

"Shrubby trees to 12 m; crown broadly conical, dense. Bark rough, furrowed, fibrous. Branchlets comblike, 0.5-1 mm diam. Leaves with conspicuous, pitlike, abaxial gland that produces drop of resin, sometimes glaucous. Pollen cones 2-3 × 2 mm; pollen sacs 3-5. Seed cones globose, mostly 1.5-2.5 cm, brown or gray, not glaucous; scales 3-4 pairs, smooth except for erect conic umbos, 2-4 mm. Seeds 2-5 mm, light to medium brown, sometimes slightly glaucous" (Eckenwalder 1993).

"Among all the true Cypresses of North America this one is unique in having flattened branchlets always lying all in one plane, to form a 'spray' ... instead of bristling all around the twig as in most other species of Hesperocyparis" (Eckenwalder 1993).

Distribution and Ecology

USA: California at 300-850 m in chaparral and foothill woodland, often on serpentine (Eckenwalder 1993); also at two locations in southwest Oregon (F. Callahan email 2010.09.28; both locations supported by herbarium collections). Hardy to Zone 8 (cold hardiness limit between -12.1°C and -6.7°C) (Bannister and Neuner 2001). See also (Thompson et al. 1999).

Data from USGS (1999).

Frank Callahan (email 2010.10.22) reports seeing western gray squirrels (Sciurus griseus) collecting the cones of this species, eating a portion of the outer cone, and discarding the rest. He also observed numerous seedlings in the area where this activity was occurring. I believe this is the first report of Hesperocyparis seed being disseminated by squirrels.

Remarkable Specimens

Frank Callahan (email 2010.1.17) reports a tree in Aukum, CA that is about 116 cm diameter and 13.7 m tall; photo at right. This is bigger than the largest specimen as reported by American Forests (2000), which Frank also discovered, in 1981.

Ethnobotany

No data as of 2023.12.16.

Observations

Peattie (1950) noted its occurrence "Irregularly scattered on the west slopes of the Sierra Nevada (Aukum in Amador County, Grass Valley in Nevada County at about 2500 feet; Texas Hill and Indiana Creek in Yuba County) and ... in the inner northern Coast Ranges at Hough Springs and Reiff in Lake County, and at Aetna Springs, Napa County; also near Ukiah in Mendocino County." Tim Ives (email, 2002.11.17) also notes that it formerly occurred at Whiskeytown, California, at a site since submerged beneath the Whiskeytown reservoir; and near the former Betty May mine in the Clear Creek mining district of Shasta Co. just west of the Whiskeytown grove, near the Shasta/ Trinity Co. line. He adds (e-mail, 2008.10.02) that trees grown from seed from the Whiskeytown grove can be found in the vicinity. One is at the Whiskeytown National Recreation Area visitor center on CA-299, between the visitor center and the highway on a short little trail that goes around behind the visitor center. It is marked with a sign. He also reports that the park botanist has been involved in efforts to outplant seedlings from the original, now submerged Whiskeytown grove at locations throughout the park, and that the area contains several mature trees that were transplanted in the early 1960s from the Whiskeytown grove to homesteads in the vicinity.

Remarks

The epithet honors James McNab (1810-1878), Curator of the Edinburgh Botanic Garden at the time the species was described (Jepson 1923). McNab is now remembered chiefly for his 1834 Mexican collecting trip, from which he successfully introduced the poinsettia. Although the species was described by Andrew Murray, a Scots politician who also made a name for himself studying insects and conifers, it was actually collected by A.F. Beardsley, a professional seed collector working for Mr. Murray. Rogers (1998) provides an engaging sample of some of Beardsley's writing.

Citations

American Forests 2000. The National Register of Big Trees 2000. Washington, DC: American Forests.

Bartel 2009: described in Adams, R. P., J. A. Bartel and R. A. Price. 2009. A new genus, Hesperocyparis, for the cypresses of the western hemisphere. Phytologia 91(1):160-185.

Jepson, W. L. 1923. The Trees of California, ed. 2. Description of C. macnabiana reproduced HERE, courtesy of the Cupressus Conservation Project website.

Murray, A. 1855. Description of new coniferous trees from California. Edinb. New Philos. J. 1:284-295 (p. 293).

Rogers, David. 1998. An addendum on the botanical history of Santa Lucia fir, Abies bracteata, with excerpts from the notes and letters of early collectors. Double-Cone Quarterly 1(3). http://www.ventanawild.org/news/ws98/slfirs2.html, accessed 2007.01.01.

See also

Elwes and Henry 1906-1913 at the Biodiversity Heritage Library. This series of volumes, privately printed, provides some of the most engaging descriptions of conifers ever published. Although they only treat species cultivated in the U.K. and Ireland, and the taxonomy is a bit dated, still these accounts are thorough, treating such topics as species description, range, varieties, exceptionally old or tall specimens, remarkable trees, and cultivation. Despite being over a century old, they are generally accurate, and are illustrated with some remarkable photographs and lithographs.

Farjon (2005) provides a detailed account, with illustrations.

Griffin and Critchfield (1972).

Last Modified 2023-12-17