Common Names

NEZUKO, KUROBE (Ohwi 1965), Japanese arborvitae (Chambers 1993).

Taxonomic notes

Syn: T. japonica Maximowicz 1866, T. gigantea Nutt. var. japonica (Maxim.) Franch. & Savatier 1875, Thujopsis standishii Gordon 1862 (Farjon 1998).

Description

Tree to 18 m tall. Bark red-brown, fibrous; crown broadly pyramidal; branches spreading. Branchlets thick, flattened, 1.5-2.5 mm wide. Leaves deep green, facial leaves without abaxial gland, apex subacute; lateral leaves slightly shorter than or as long as facial leaves, apex incurved. Pollen cones 1.5-2 mm long, black. Seed cones terminal, deep brown, obovoid, 8-10 mm diameter; cone scales 10-12, middle 4-6 scales fertile, each with 3 seeds. Seeds 5-6 mm long; wings 6-7 × 2-2.5 mm (Fu et al. 1999 and pers. obs. of cultivated trees). In general, very similar to other species of Thuja in foliage and bark characters; trees are most easily distinguished according to cones, as shown in the scanned image at left.

Range

Japan: mountains of Honshu and Shikoku (Ohwi 1965), where it grows primarily in subalpine and upper cool temperate forests in the company of other conifers including Abies homolepis, Taxus cuspidata, Tsuga diversifolia, and Pinus parviflora (Kira and Yoshino 1967).

Big Tree

Oldest

Dendrochronology

Some data are available. The sampled trees have ages as great as 283 years on trees to 47 cm DBH and 22.5 m height (Forestry and Forest Products Research Institute 1998).

Ethnobotany

The light, soft wood is used for bent wood ware, kegs, tubs, etc (Anonymous [no date]). It is also used as an ornamental tree in the U.S., USDA Zone 7.

Observations

The Sado Cedar Virgin Forest in Kita-akita county, Akita prefecture, is said to be a good place to see it. In these forests it grows with fine stands of Cryptomeria japonica (FAS 1998).

Remarks

This is one of the "Five Sacred Trees of Kiso," a group that also includes hinoki (Chamaecyparis obtusa), sawara (C. pisifera), asuhi (Thujosis dolobrata), and koya maki (Sciadopitys verticillata). These trees were not precisely sacred, but were the most valuable trees of the great Kiso Forest and were therefore protected during feudal times from cutting by common people; they were only cut for the residences and temples of the wealthy and powerful families in the area, and cutting by commoners received the same penalty as poaching - death. "Shinto shrines are generally built of unfinished wood from the five trees. The Kiso has supplied hinoki trees for the cyclical rebuilding of the Ise Shrines, floating them down the Kiso river... Kiso timber was also prized for constructing government buildings and the mansions of the daimyo in Edo" (Stanley and Irving 1996).

Citations

Anonymous. [no date]. Nezuko. http://www.cnr.berkeley.edu/departments/espm/forsci/woodcoll/boards.htm#NEZUK, accessed 2001.02.20.

FAS. 1998. Todo and Sado Cedar Virgin Forest. http://www.media-akita.or.jp/akita-monuments/sugiE.html, accessed 2001.02.20.

Forestry and Forest Products Research Institute. 1998. Tree Rings Data Base for Stem Analysis. http://cs.ffpri.affrc.go.jp/fdb/TRINGS/11-28/trings-e.html, accessed 2001.02.20 (need to query database for "Thuja standishii").

Kira, T. and M. Yoshino. 1967. Thermal distribution of Japanese conifer species. Contributions in Honor of Dr. Kinji Imanishi on the occasion of his sixtieth birthday, Vol. 1, Natural history-ecological studies (ed. by M. Morisita and T. Kira), pp. 133-161. Chuo-Koron Sha, Tokyo (in Japanese).

Stanley, Thomas A. and R.T.A. Irving. 1996. Kiso Forest. http://hkuhist2.hku.hk/nakasendo/kisofrst.htm, accessed 2001.02.20.

See Also

Carrière. 1867. Traité Gén. Conif., ed. 2, 1: 108.

Farjon 2005.