Cryptomeria is a monotypic genus of conifer in the cypress family (Cupressaceae), order Pinales, containing a single species, Cryptomeria japonica — commonly known as Japanese cedar, Japanese redwood, or by its Japanese name, Sugi. It is considered endemic to Japan, though populations long cultivated in China were historically mistaken for native stands; genetic analysis of one famous ancient Chinese population (Tianmu Mountain) instead supports introduction from Japan.
The tree is very large and evergreen, reaching up to 60 m tall and 4 m in trunk diameter, with red-brown bark that peels in vertical strips, spirally arranged needle-like leaves 0.5–1 cm long, and globular seed cones 1–2 cm across bearing 20–40 scales. It is superficially similar to the giant sequoia but distinguished by its longer leaves, smaller cones, and harder trunk bark. Cryptomeria favors forests on deep, well-drained soils under warm, moist conditions, growing fast there but faring poorly in poor or cold, dry soils. Its fossil record is extensive, with material described from the Late Eocene through the Pleistocene across Russia, China, Japan and Europe.
Beyond Japan, the genus has been extensively introduced and cultivated, most notably in the Azores, where it was planted from the mid-19th century for timber and now dominates the archipelago's production forest. It is also grown in the Darjeeling and Sikkim regions of India, where it is called Dhuppi, and widely as an ornamental across Britain, Europe, North America and the Himalaya. Its fragrant, weather- and insect-resistant wood is used for construction, furniture, casks and plywood, and the traditional daisugi coppicing method is still used in Japan to harvest logs from a single trunk repeatedly.
Sugi holds deep cultural significance in Japan, commonly planted around temples and shrines; the famous Cedar Avenue of Nikkō, over 65 km long, was planted in tribute at the funeral of shōgun Tokugawa Ieyasu. Jōmon Sugi, an ancient specimen on the UNESCO World Heritage site of Yakushima, is estimated at 2,170 to 7,200 years old and ranks among the oldest living trees in Japan.
Etymology
The genus name Cryptomeria literally means "hidden parts." In Japan the tree is known as Sugi (杉); in English it is called Japanese cedar or Japanese redwood.
Distribution
Cryptomeria is considered endemic to Japan, though long-cultivated Chinese populations were historically mistaken for native stands. It has been widely introduced elsewhere, most notably the Azores (planted from the mid-19th century for timber, now covering over 12,698 hectares there), as well as Darjeeling and Sikkim in India, and as an ornamental across Britain, Europe, North America and the eastern Himalaya.
Ecology
Cryptomeria grows fastest in forests on deep, well-drained soils under warm, moist conditions, and is intolerant of poor soils and cold, drier climates. It serves as a food plant for the larvae of several Endoclita moth species, and its pollen (along with that of hinoki cypress) is a major cause of hay fever in Japan.
Cultivation
The timber is fragrant, weather- and insect-resistant, soft, and lightweight, used for staves, tubs, casks, furniture, light construction, boxes and plywood; wood buried underground turns dark green and is especially prized. The species is also widely grown as an ornamental, with numerous dwarf cultivars for rock gardens and bonsai and several holding the Royal Horticultural Society's Award of Garden Merit. In Japan, the traditional daisugi coppicing method is sometimes used to harvest repeated crops of logs from a single tree.
Cultural Uses
Sugi is commonly planted around Japanese temples and shrines, most famously along the more than 65-km Cedar Avenue of Nikkō, planted in tribute at the funeral of shōgun Tokugawa Ieyasu. Jōmon Sugi, an ancient tree on the UNESCO World Heritage site of Yakushima, is estimated to be between 2,170 and 7,200 years old, and cryptomeria forests feature in Japanese literature such as Yasunari Kawabata's The Old Capital.
Taxonomy Notes
Cryptomeria is monotypic, containing only Cryptomeria japonica, and sits in family Cupressaceae, order Pinales (confirmed by GBIF). Chinese populations long treated as a distinct variety (var. sinensis) or species (C. fortunei) show no consistent morphological difference from wild Japanese material, and genetic analysis of the ancient Tianmu Mountain population supports introduction from Japan rather than native Chinese origin. The genus also has an extensive fossil record spanning the Late Eocene to the Pleistocene across Russia, China, Japan and Europe.
