Chamaecyparis obtusa var. formosana / Taiwan yellow cypress

Chamaecyparis obtusa var. formosana, as described in 1914 by Alfred Rehder (1863-1949), in The Standard Cyclopedia of Horticulture vol.2, is commonly known as Taiwan yellow cypress, as well as 黃檜 (Huáng guì) in the Chinese language.

Description. Taiwan yellow cypress is an evergreen, coniferous variety of Hinoki cypress (C. obtusa). It differs from the type in the following ways:

  • seed cones are smaller, measuring 0.28 to 0.36 inch (7 - 9 mm)
  • seed scales have a small central depression
  • geographical differences that result in decreased cold-hardiness.

Distribution. This specific variety is native to Taiwan — Hualien, Ilan and Xinchu Xians, especially Yuanyanghu (Lake) Nature
Preserve, where it can be found growing at elevations of 5,200 to 9,500 feet (1,600 - 2,900 m) sea level. It generally grows in mesic (mixed) Chamaecyparis and broad-leaved forest; also exposed sites at high elevation.

Hardy to USDA Zone 8 — cold hardiness limit between 10° and 20°F (-12.1° and -6.7°C), and well-suited for cultivation in semi-tropical climate zones with high humidity and copious summer rainfall.

Chamaecyparis obtusa var. formosana, Guanwu National Forest, Taiwan.
Photo by lienyuan lee, via Wikipedia, CC BY 3.0, public domain photo
Chamaecyparis obtusa var. formosana — a closeup of foliage detail. Photo taken during summer 2002 at Plant Delights Nursery in North Carolina, USA.
Photo by Bill Barger