Chamaecyparis thyoides description

Chamaecyparis thyoides (Linnaeus) Britton, Sterns, & Poggenburg 1888

Common Names

Atlantic white-cedar, southern white-cedar (3), white cypress (4), swamp cedar.

Taxonomic notes

Syn: Cupressus thyoides Linnaeus 1753; Thuja sphaeroidea Spreng.; Chamaecyparis sphaeroidea (Spreng.) Spach.

One subspecies, Chamaecyparis thyoides subsp. henryae (Li H.L.) E. Murray, sometimes treated as a separate species Ch. henryae Li H.L.; syn. Ch. thyoides var. henryae (Li H.L.) Little. Li (1962) segregated the disjunct Gulf Coast populations in Alabama, Florida, and Mississippi as Ch. henryae based on smoother bark, less flattened branchlets, lighter yellowish green foliage, steeper angle of leaf appression to the stem, more prominently keeled but less glandular leaves, and slightly larger cones, seeds, and seed wings. These features contrasted with phenotypes found in the 'northern and mid-Atlantic' populations, and Li proposed a relationship to Ch. nootkatensis rather than to Ch. thyoides . "Preliminary comparison of herbarium material from the Southeast (including populations in Georgia and Florida) leads to retention of Ch. thyoides as a subtly variable complex with the imperfectly differentiated Ch. henryae at one end of the range" (3); although close to typical Ch. thyoides and not to Ch. nootkatensis , it is ecologically adapted to greatly different climatic conditions, and field and genetic research is required before the taxon can be dismissed or reduced in status.

"A. J. Rehder (1949) listed, with bibliographic citations, 30 published varieties and forms best considered as cultivars" (3).

Description

Trees to 20 m tall and 80 cm dbh. "Bark dark brownish red, less than 3 cm thick, irregularly furrowed and ridged. Branchlet sprays fan-shaped. Leaves of branchlets to 2 mm, apex acute to acuminate, bases of facial leaves often overlapped by apices of subtending facial leaves; glands usually present, circular. Pollen cones 2-4 mm, dark brown; pollen sacs yellow" (3). Seed cones maturing and opening the first year, commonly somewhat irregular or asymmetrical, 4-9 mm broad, glaucous, bluish purple to reddish brown, not notably resinous; scales 6-8(10), each scale depressed and minutely mucronate, the apical pair of scales fused. Seeds 1-2 per scale, 2-3 mm, wing narrower than body (3, 5).

In addition to the foliage differences noted above, subsp. henryae differs from the type in having more open growth with less congested branchlets; it also can potentially become a larger tree (c.f. Big Tree) (5).

Range

USA: Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Delaware, Pennsylvania, Maryland, Virginia, North Carolina, South Carolina, Georgia, at 0-500 m, chiefly in bogs and swamps of the Atlantic Coastal Plain (3). See also (7). Subsp. henryae in Florida, Alabama and Mississippi, in bogs and swamps of the Gulf Coastal Plain (5). USDA hardiness zone 5; subsp. henryae zone 8.

Big Tree

Subsp. henryae:height 27 m, DBH 150 cm, crown spread 13 m, located in Brewton, Alabama (2).

Oldest

Ages exceeding 1000 years are cited, without supporting data (6).

Dendrochronology

Ethnobotany

Observations

Remarks

Citations

(1) Silba 1986 .
(2) American Forests 1996 .
(3) Michener, David C. at the Flora of North America web site .
(4) Dallimore et al. 1967 .
(5) M.P. Frankis, personal observations contributed 3-Feb-1999.
(6) Burns & Honkala 1990 , p.107.

(7) Robert S. Thompson, Katherine H. Anderson and Patrick J. Bartlein. 1999. Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America. U.S. Geological Survey Professional Paper 1650 A&B. URL= http://greenwood.cr.usgs.gov/pub/ppapers/p1650-a/pages/conifers.html, accessed 22-Jan-2000.