Cryptomeria Japonica

''Cryptomeria'' (literally "hidden parts") is a monotypic genus of conifer in the cypress family Cupressaceae. It includes only one species, ''Cryptomeria japonica'' ( syn. ''Cupressus japonica'' L.f.). It is considered to be endemic to Japan, where it is known as . The tree is also called Japanese cedar or Japanese redwood in English. It has been extensively introduced, and cultivated for wood production on the Azores and elsewhere.

Description

''Cryptomeria'' is a very large evergreen tree, reaching up to tall and trunk diameter, with red-brown bark which peels in vertical strips. The leaves are arranged spirally, needle-like, long; and the seed cones globular, diameter with about 20–40 scales. It is superficially similar to the related giant sequoia (''Sequoiadendron giganteum''), from which it can be differentiated by the longer leaves (under in the giant sequoia) and smaller cones ( in the giant sequoia), and the harder bark on the trunk (thick, soft and spongy in giant sequoia). Prior to 1916, the sylvics expert E.H.Wilson measured a sugi at the village called "Sugi", Toso Perfecture, Shikoku Island, Japan, which measured in height, and in girth at breast height.

Endemism

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.

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.

Biology

''Cryptomeria'' grows in forests on deep, well-drained soils subject to warm, moist conditions, and it is fast-growing under these conditions. It is intolerant of poor soils and cold, drier climates.

It is used as a food plant by the larvae of some moths of the genus '' Endoclita'' including ''E. auratus'', ''E. punctimargo'' and ''E. undulifer''. Sugi (and hinoki) pollen is a major cause of hay fever in Japan.

Fossil record

The earliest fossil record of ''Cryptomeria'' are descriptions based on vegetative organs of †''Cryptomeria kamtschatica'' of the Late Eocene from Kamchatka, Russia and †''Cryptomeria protojaponica'' and †''Cryptomeria sichotensis'' from the Oligocene of Primorye, Russia. Several fossil leafy shoots of †''Cryptomeria yunnanensis'' have been described from Rupelian stage strata of the Lühe Basin in Yunnan, China.

From the Neogene, ''Cryptomeria'' is well represented as seed cones, leafy shoots and wood in the fossil records of Europe and Japan. †''Cryptomeria rhenana'' was described from the early Late Miocene to the Late Miocene of Rhein in Morsbach, Germany, from the Early and Middle Pliocene of Northern Italy, to the Middle Pliocene of Dunarobba, Italy and to the Early Pleistocene of Umbria, Italy. †''Cryptomeria anglica'' was described from the Late Miocene of La Cerdana, Spain, to the Late Middle Miocene of Brjánslækur, Iceland and from the Late Miocene to the early Pliocene