Chamaecyparis obtusa ( Japanese cypress, hinoki cypressRushforth, K. (1987). 074702801X, Helm. 074702801X
Description
It is a slow-growing
tree which may reach tall
with a trunk up to in diameter. The bark is dark red-brown. The
leaf are scale-like, long, blunt tipped (obtuse), green above, and green below with a white stomatal band at the base of each scale-leaf. The
conifer cone are globose, in diameter, with 8–12 scales arranged in opposite pairs.
Related species
The plant is widespread in Japan. The related
Chamaecyparis pisifera (sawara cypress) can be readily distinguished in its having pointed tips to the leaves and smaller cones.
A similar cypress found on
Taiwan is treated by different botanists as either a variety of this species (as
Chamaecyparis obtusa var.
formosana) or as a separate species
Chamaecyparis taiwanensis; it differs in having smaller cones (6–9 mm diameter) with smaller scales, and leaves with a more acute apex.
Timber
It is grown for its very high-quality timber in Japan, where it is used as a material for building
,
, shrines, traditional
noh theatres, baths,
table tennis blades and masu. The wood is lemon-scented, light pinkish-brown, with a rich, straight grain, and is highly rot-resistant. For example,
Horyuji Temple and
Osaka Castle are built from hinoki wood. The hinoki grown in
Kiso River, used for building
Ise Shrine, are called 御神木
go-shin-boku, or "divine trees".
Ornamental cultivation
It is also a popular
ornamental tree in parks and gardens, both in Japan and elsewhere in
temperate climates, including
western Europe and parts of North America. A large number of
have been selected for garden planting, including dwarf forms, forms with yellow leaves, and forms with congested foliage. It is also often grown as
bonsai.
Cultivars
Over 200
have been selected, varying in size from trees as large as the wild species, down to very slow-growing dwarf plants under high. A few of the best known are listed below.
[Tree Register of the British Isles] Those marked
agm have gained the Royal Horticultural Society's Award of Garden Merit (confirmed 2017).
-
'Crippsii'agm
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'Fernspray Gold'agm
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'Kamarachiba'agm
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'Kosteri'agm
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'Lycopodioides' reaches up to tall, with somewhat fasciation foliage
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'Minima' – under after 20 years with mid-green foliage
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'Nana'agm
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'Nana Aurea'agm
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'Nana Gracilis'agm
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'Nana Lutea'agm – compact, slow-growing, golden yellow selection which has become very popular; yellow counterpart to 'Nana gracilis'
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'Spiralis' is an erect, stiff dwarf tree
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'Tempelhof' growing to with green-yellow foliage that turns bronze in winter
-
'Tetragona Aurea' grows to around tall, with a narrow crown and irregular branching, the scale leaves in 4 equal ranks and branchlets tightly crowded, green and gold
-
'Tsatsumi Gold'agm
Chemistry
The
chamaecypanones A and B, obtulignolide, and isootobanone can be found in the heartwood of
Chamaecyparis obtusa var.
formosana.
The biflavones sciadopitysin, ginkgetin, isoginkgetin, podocarpusflavone B, 7,7''-
O-dimethylamentoflavone, bilobetin, podocarpusflavone A, 7-
O-methylamentoflavone,
amentoflavone,
hinokinin and hinokiflavone have been confirmed in the leaves of the plant.
was first discovered in the seeds of
C. obtusa.
The
essential oil of
Chamaecyparis obtusa contains a wide range of chemical compounds, including but not limited to the following:
sabinene, elemol,
myrcene,
limonene, terpinen-4-ol, eudesmols, α-terpinyl acetate, α-terpinolene, α-
terpineol, 3-carene, α-pinene, γ-
terpinene,
camphene,
bornyl acetate, 1-methyladamantane, cuminol, eucarvone,
Cyclopentenone, 3,4-dimethyl-, 1,3-dimethyl-1-cyclohexene, calamenene, τ-muurolol,
borneol,
Alpha-cadinol,
Hinokitiol.
Some of these compounds are fragrances or intermediates used in the fragrance industry. Thus, the
C. obtusa essential oil is used in perfumery and personal care products, such as soaps, shampoos, cosmetics.
Hinoki wood is used as a traditional Japanese stick incense for its light, earthy aroma.
Essential oil distilled from its wood is uniquely scented and highly valued.
Pollen
Hinoki pollen can cause
pollinosis, a specific type of allergic rhinitis.
Chamaecyparis obtusa, along with
Cryptomeria japonica (sugi, Japanese cedar), is the leading source of allergic pollen in Japan and a major cause of hay fever in Japan.
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