Thuja koraiensis

Nakai (1919)

Common names

Korean arborvitae (Chambers 1993), or chao xian ya bai [Chinese] (Fu et al. 1999).

Taxonomic notes

No data as of 2026-01-31.

Description

Shrubs or small trees to 10 m tall and 80 cm dbh. Bark red-brown and smooth when young, gray-brown and fissured when old, soon flaking; branches ascending or spreading; young branchlets ± glaucous, soon becoming green. Facial leaves 1-2 mm, to 15 mm on leading branchlets, abaxial gland near base, apex obtuse; lateral leaves as long as or shorter than facial leaves, apex incurved. Pollen cones purplish, subglobose, 2-3 mm; microsporophylls 6-10, each with 3 or 4 pollen sacs. Seed cones dark brown when ripe, ellipsoid-globose, 7-10 × 6-8 mm; basal pair of cone scales subellipsoid, middle pairs suboblong, apical pair long and narrow. Seeds ellipsoid, flattened, ca. 4 × 1.5 mm; wings 1-1.5 mm wide. Pollination May, seed maturity September (Fu et al. 1999). See García Esteban et al. (2004) for a detailed characterization of the wood anatomy.

Distribution and Ecology

N Korea and China: S Jilin (Changbai Shan) at 700-1,800 m elevation (Silba 1986, Fu et al. 1999). Hardy to Zone 5 (cold hardiness limit between -28.8°C and -23.3°C) (Bannister and Neuner 2001).

It is a vulnerable species in China (Fu et al. 1999).

Remarkable Specimens

No data as of 2026-01-31.

Ethnobotany

No data as of 2026-01-31.

Observations

No data as of 2026-01-31.

Remarks

The epithet refers to the type locality, in Korea.

Citations

Chambers, Kenton L. 1993. Thuja. Flora of North America Editorial Committee (eds.): Flora of North America North of Mexico, Vol. 2. Oxford University Press.

Nakai, S. 1919. Notulae ad Plantas Japoniae et Koreae XXI. Botanical Magazine Tokyo 33:196. Available: Biodiversity Heritage Library, accessed 2025.12.24.

See also

The species account at Threatened Conifers of the World.

Farjon 2005.