Japanese Cedar

Basic Information
Tree ID: 
Genus and species: 
The Japanese Cedar looks dorky at first, and that's because, well, it is. But it's also dangerous. That's right. What looks like a dorky tree to you is known in Japan as the cause of hay fever outbreaks nationwide, Public Enemy #1. It's so severe that the Japanese government intervened with legislation to develop low-pollen producing varieties of the plant. You're gonna want to learn more.
Doug Streat, Kevin Ig-Izevbekhai, Ragini Luthra
Collected Data
Tree shape: 
Irregular Pyramidal
Date of tree entry: 
2.95 m
Diameter at breast height: 
0.05 m

The bark of C. japonica can vary in color but is typically reddish brown and highy textured. It is characterized by its ability to be peeled in long strips; unlike many flowering trees, it is a very ostentatious, soft bark.
Twigs & branches
The Japanese cedar has many droopy branches, with many offshoots from each branch. The branches grow thinner as the tree ascends vertically, typically converging at a narrow crown. Main are usually attached to a narrow centra trunk. This particular specimen is interesting, and somewhat unique from the norm, in that their appear to be several offshoots at the base of the tree, though only once clearly develops into an established trunk. Branches are covered in needles, discussed further in the foliage section, below.
Foliage for the Japanese cedar is similar to that found on any conifer—thin, simple needles covering the length of the branches. In the case of C. japonica, needles are arranged spirally around branches and they are awl-like in shape. Their length is on average 1/2 to 3/4 inches. As the Japanese cedar is a variety of evergreen, the color is typically a shade of green, often depenent on the time of year and the climate; these needles last approximately 4 years. The foliage is soft and waxy.
Reproductive Structures
Cryptomeria japonica is a non-flowering plant. Instead of having reproductive structures as seen in angiosperms, its reproductive cycle is on par with that observed in gymnosperms. The tree is monoecious and consequently produces both male cones and female cones (pictured above). Male cones (staminate cones) are characterized by being very small and abundant, while female, seed-bearing cones (fruiting or ovulate cones) are larger with woody scales. Pollen from male cones enters the micropyle of female cones; after fertilization is completed, seeds develop beneath the scales of the female cones, and eventually these seeds proliferate.
The analog to the fruit in gymnosperms is the female cone which bears the seed. Pictured here are several examples of female cones for C. japonica. Two fertilized seeds can be found under the scales, allowing for the tree to spread in many of the same ways angiosperms do through actual fruit. Unlike angiosperms, however, the Japanese cedar's fruit analog is not showy and does not attract wildlife.
  • Evergreens don't change with the season, but they do ocassionally "bronze" in the winter or in colder weather.
Natural range of distribution: 
The Japanese cedar is native to Japan and parts of China. It is also cultivated in Canada, India, Indonesia, Iran, New Zealand, South Africa, Tanzania, the UK, and the USA. It grows especially well in Zones 5 and 6 in the United States. It primarily grows in altitudes of 650 - 2400 meters, where mean annual temperature is 10 - 18 º C and mean annual rainfall is 1500-2500 mm. It typically grows in free-draining, moist soil.
Origin, history, and uses: 

Cryptomeria is a large evergreen tree, related to the bald cypress. The etymology of its name literally refers to “hidden things,” a reference to the lack of obvious flower parts, discussed elsewhere on this page. It is an ancient tree, thought to be at least 75 million years old and as such has long been fundamental to the cultures of Japan and China, where it is grown natively. In fact, it is the national tree of Japan, where it is called “sugi.”

In Japan, Sugi is revered, often planted around places of worship. It is a tall, impressive tree when full grown and is fundamental to the country’s national identity. In contrast, in the United States it is grown as an exotic plant, imported for very different reasons, especially for providing shade to properties and defining borders.

In Japan and China it has long been cultivated for its wood, a soft, fragrant timber. This wood is used extensively for ornament, especially due to its remarkable color variation, though it is also used, less commonly for construction. The tree is also cultivated for its resin from which cryptopimaric acid and phenolic acid are isolated, for tannins, for essential oils and medicinal oils, and aromatic incense.

The Japanese cedar is an evergreen; as such, the phenology involves for the most part stagnancy throughout the seasons. It typically polinates early in the year, allowing pollen to burrow through female cones throughout the summer and fall, however this cycle is not consistent. Interesting to note, however: the cones and needles, both, may be on the tree for several years at a time. Unlike many trees which change on an annual basis, the Japanese Cedar's life cycle involves a full changeover of reproductive parts and foliage every 4-8 years or so.
Media and Arts
This video discusses the growth pattern of Cryptomeria japonica.