Cryptomeria (literally “hidden parts”) is a monotypic genus of conifer in the cypress family Cupressaceae, formerly belonging to the family Taxodiaceae. It includes only one species, Cryptomeria japonica (syn. Cupressus japonica L.f.). It used to be considered by some to be endemic to Japan (see remark below under ‘Endemism’), where it is known as Sugi (杉, lit. “Hair Tree”). The tree is called Japanese cedar or Japanese redwood in English. It has been extensively introduced and cultivated for wood production on the Azores.
Sugi has been cultivated in China for so long that it is frequently thought to be native there. Forms selected for ornament and timber production long ago in China have been described as a distinct variety Cryptomeria japonica var. sinensis (or even a distinct species, Cryptomeria fortunei), but they do not differ from the full range of variation found in the wild in Japan, and there is no definite evidence the species ever occurred wild in China. Genetic analysis of the most famous Chinese population, on Tianmu Mountain, containing trees estimated to be nearly 1000 years old, supports the hypothesis that the population originates from an introduction.
However, the famed Japanese botanist and plant ecology expert Akira Miyawaki has proven since the 1970s that trees such as Japanese Cedar, Cypress and Larch Pine, i.e. including Cryptomeria, which were so far believed to be native to Japan, had in fact been progressively introduced into Japan over many centuries by foresters in order to produce timber. Akira Miyawaki calculated that only about 0.06% of contemporary Japanese forests are actual indigenous forests.
Outside of its native range, Cryptomeria was also introduced to the Azores in the mid 19th century for wood production. It is currently the most cultivated species in the archipelago, occupying over 12,698 hectares, 60% of the production forest and about 1/5 of the region’s total land area.