Chamaecyparis

Spach 1841

Common names

Cypress (Rushforth 1987, Welch and Haddow 1993), white-cedar, false-cypress, faux-cypres (Michener 1993).

Taxonomic notes

A genus generally regarded as comprised of 6 species:

• Chamaecyparis formosensis
• Chamaecyparis hodginsii
• Chamaecyparis lawsoniana
• Chamaecyparis obtusa
• Chamaecyparis pisifera
• Chamaecyparis thyoides

Some authors include all species of Chamaecyparis in the genus Cupressus (Michener 1993), but genetic studies indicate they are generally not particularly closely related (Brunsfeld et al. 1994, Gadek and Quinn 1993, Mao et al. 2010). Two species sometimes included in this genus, Ch. funebris and Ch. nootkatensis, are here assigned to Cupressus and Callitropsis, respectively (Rushforth 1987, Welch 1991, Farjon 1998, Gadek et al. 2000, Mao et al. 2010) on the basis of various lines of evidence. Ch. hodginsii was formerly assigned to the monotypic genus Fokienia, but both morphological and molecular studies have firmly established it as nested within Chamaecyparis. Two other taxa sometimes treated as species (Ch. henryae and Ch. taiwanensis) are usually treated as subspecies or varieties of Ch. thyoides and Ch. obtusa respectively. Cultivated juvenile forms of several species have been referred to the superfluous Retinospora Siebold et Zuccarini.

Description

Tall monoecious trees (rarely shrubs) of pyramidal habit, the bark smooth, peeling off in strips or scales or fissured into ridges. Leading shoots nodding, branches spreading, the branchlets dorsiventrally flattened, rarely (Ch. thyoides) more or less terete or rhombic in cross section, in fan-shaped or pinnately flattened sprays. Leaves opposite in 4 ranks. Juvenile leaves subulate. Mature leaves opposite, scale-like, lateral and facial pairs of differing shape, similar in size or the facial pairs smaller, and closely overlapping, ovate to rhombic, acuminate to obtuse, entire. Staminate cones ovoid to oblong, yellow or (usually) red, stamens decussate, with 2-3 pairs of sporophylls, each sporophyll with 2-4 pollen sacs. Ovulate cones maturing and opening in 6-8 months from pollination, shed soon after seed release, globose to ovoid-globose, green or violet, often glaucous, maturing brown, 4-12(-14) mm; scales persistent, (2-)3-5(-6) pairs, peltate or basifixed, thick and woody, the terminal pair fused. Seeds (1)2-4(5) per scale, slightly compressed, with 2 equal, membranaceous wings. Cotyledons 2, rarely 3. x = 11 (Li 1975, Michener 1993, Walker 1976).

Distribution and Ecology

North America, Japan and Taiwan (Li 1975).

Remarkable Specimens

Chamaecyparis formosensis has the largest individuals. Ages to 1,755 years are reliably reported for C. lawsoniana. C. formosensis likely also achieves great ages, but I haven't seen documentation for it.

Ethnobotany

The genus is of immense importance to modern horticulture; two species (Ch. lawsoniana, Ch. pisifera) account for perhaps 80-90% of the ornamental conifers grown in British gardens.

Observations

See the various species.

Remarks

The name Chamaecyparis is derived from the Greek: chamai = on the ground, and kyparissos = cypress (Walker 1976).

Several of the species show high variation in seedbeds, leading to the selection for horticultural use of many hundred cultivars. "Three [Ch. lawsoniana, Ch. pisifera, Ch. obtusa] are very variable and have given rise to a ridiculous flood of selected seedlings and mutations, many of which are so similar to others as to be just not worth perpetuating. Unfortunately this flow still continues. Very great restraint should now be exercised in introducing fresh forms that will add more names to our listings but no more beauty to our gardens" (Welch and Haddow 1993). This exasperated remark is followed by a 57 page list of Chamaecyparis cultivar names, including 29 pages with 559 names in Ch. lawsoniana alone - no wonder!

Citations

American Lumberman. 1911.11.11. "The Realization of a Great Commercial Dream." American Lumberman n.v. (November 11, 1911):43-142.

Clinton-Baker, H. 1913. Illustrations of Conifers, Vol. 3. Privately printed: Hertford. Available at openlibrary.org.

Welch, H.J. 1991. The Conifer Manual vol. 1.

Welch, H.J. and G. Haddow 1993. The World Checklist of Conifers.

This page co-edited with M.P. Frankis, 1999.02.

See also

Farjon (2005).