Distribution of Cupressus macnabiana (Griffin and Critchfield 1972).

Cupressus macnabiana

A. Murray 1855

Common Names

MacNab cypress (Elias 1987).

Taxonomic Notes

Little (2006) has proposed, with strong support from molecular/genetic data (cf. Little et al. 2004), that Cupressus be divided into new world and old world genera. The new world species, which are more closely related to Juniperus than to the old world species, he assigns to Callitropsis Oersted; while the old world species remain in Cupressus L. This species would then become Callitropsis macnabiana (A. Murray bis) D.P. Little.

"In the inner north Coast Ranges C. macnabiana and C. sargentii produce the only known natural hybrids in Cupressus (Lawrence et al. 1975)" (Eckenwalder 1993). Syn.: Cupressus nabiana Mast. 1891.

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 Cupressus" (Eckenwalder 1993).

Range

USA: California at 300-850 m in chaparral and foothill woodland, often on serpentine (Eckenwalder 1993). See also (Thompson et al. 1999).

Big Tree

Height 17 m, dbh 125 cm, crown spread 14 m; in Amador County, CA (American Forests 2000).

Oldest

Dendrochronology

Ethnobotany

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 (e-mail, 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. It soon became the premier Christmas ornamental (after the Christmas tree, of course). Although the species was described by Andrew Murray, a Scots politician who also made a name for himself studying insects and confers, 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

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

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.