Descriptions and a Key to Cultivars of Japanese Cedar Cultivated in the Eastern United States

Abstract

<jats:p>Japanese cedar, <jats:italic>Cryptomeria japonica</jats:italic> (Thunb. ex L.f.) D. Don [Cupressaceae Bartling, formerly assigned to Taxodiaceae Warm.] is increasing in popularity as a landscape plant in the eastern United States. A taxonomic study of cultivars grown in the eastern United States was conducted. Forty-five cultivars were recognized. Each cultivar bears synonymy, a quantitative morphological description newly described from field data, herbarium vouchers, references to original literature and observational notes. A glossary of taxonomic terms relevant to <jats:italic>Cryptomeria</jats:italic> is presented. A taxonomic key is presented for segregation of cultivars that should assist professional plantsmen in identification of taxa cultivated in the eastern United States.</jats:p>

Differences in Winter Browning among Japanese-cedar Cultivars Are Not Due to Variation in Ploidy Levels

“…In an attempt to exploit this phenomenon to develop new ornamental cultivars, induced tetraploids have been developed (Contreras et al, 2010); however, it remains to be seen if the same gains in antioxidant activity and improved winter color will be observed as in previous studies. In addition to Rouse et al (2000), Dirr (2009) and Krüssman (1985) reported on the variability in winter foliage color among japanesecedar cultivars, including a number that were included in the current study. There has not been a comprehensive evaluation of cultivars Rouse et al (2000).…”

“…In addition to Rouse et al (2000), Dirr (2009) and Krüssman (1985) reported on the variability in winter foliage color among japanesecedar cultivars, including a number that were included in the current study. There has not been a comprehensive evaluation of cultivars Rouse et al (2000). y Means within column followed by the same letters are not significantly different based on Tukey's honestly significant difference (a = 0.05).…”

“…The 56 accessions included in the study were chosen based on availability as well as differences in winter browning. Included in Table 1 are observations of winter color for 33 accessions from the current study from Rouse et al (2000). These data are included to demonstrate the variability of winter foliage color among japanese-cedar cultivars.…”

“…These data are included to demonstrate the variability of winter foliage color among japanese-cedar cultivars. Observations by Rouse et al (2000) were made at multiple locations from Atlanta, GA, to Philadelphia, PA, over a 3-year period. Conditions were not standardized; therefore, observations for winter color cannot be considered as a quantitative tool.…”

“…Winter browning is highly variable among ornamental cultivars of japanese-cedar. Rouse et al (2000) described 45 cultivars of japanesecedar growing in the eastern United States including variability in foliage color during winter from brown to dark green. Our hypothesis was that a difference in ploidy level among cultivars is related to the variation in winter color and that cultivars that remain greener during winter were tetraploids.…”