Botany Boy

A common companion of the Japanese cedar, Cryptomeria japonica, is the famous Japanese hinoki, Chamaecyparis obtusa.  Hinoki is a smaller tree, however in ancient times massive ones existed – alas those forests of old are long gone.  Nevertheless, this tree has a special place in Japanese culture, revered mostly for its wood, but also for the fragrant essential oils found throughout its tissues.

Chamaecyparis obtusa a massive evergreen coniferous tree reaching 35 meters in height, and with a trunk up to a meter in diameter.  The bark is reddish brown to silvery and grows in long strips.  In young trees these can flake off in thin strips, but older trees have more compact bark generally, and thicker in substance.

The branches grow in  a whorl up the trunk and tend to hang down a bit.  Young trees are cylindrical, having broad and rounded crowns with old trees having more irregular branching and more pendulous branches.  Older specimens can have branch-less trunks for the first several meters, especially in low light conditions such as plantation forests.

The leaves are dark green to blue-green, scale-like in appearance and blunt at their tips.  They grow on branchlets that are spreading, fan-like, and tend to be in a relatively flat plane.  These branchlets break off intact when they fall rather than falling apart on the tree. The pollen cones and seed cones are born separately, but on the same tree (monoecious habit).  The red-brown pollen cones grow singly on the outermost twigs and are roughly conical shaped and are only 3-5 mm long each.  The seed cones start out growing bright green and eventually turn a rich brown.  They are nearly perfectly round and are about 2 cm across.

This common conifer is found in southern Japan from western Honshu, Shikoku, and Kyushu.  The variety formosana is reported from Taiwan and sometimes is considered a separate species, C. taiwanensis.  Both varieties are very rare in the wild with just a few remnant populations. While hinoki prefers moist woodlands, it also can be found on exposed ridge-lines, from 0-1000+ meters elevation.  Trees can be in mixed stands with other conifers or most often with broad leaf trees, both deciduous and evergreen.
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The warmer forests of Japan are home to a large evergreen shrub which is now grown world wide, the so called Japanese laurel, Aucuba japonica.  At first glance this plant reminds one of a rhododendron in growth habit and a holly for its berries, but in fact it is more closely related to the dogwoods.  In Japan it is at home in the wet valleys and ravines of mountain forests.

Aucuba japonica is a large evergreen shrub or small tree standing 2 to 5 meters in height.  It has a ranging habit with branches bending and twisting every which way in the deep shade of its mountain home, in search of light.  The leaves grow opposite each other and seem to dangle off the ends of the long, sparsely branched stems in clusters.  Despite this, the overall look of the plant is full, perhaps due to the large size of the dark green serrated leaves.  Each is 7-25 cm long and 4-10 cm wide.  The serrations are few, but large.

The leaves give off a lustrous sheen that can seem bluish from a distance, giving the plant its Japanese name, aoki, meaning “blue tree”. It is one of the few plants that actually seems to favor conifer plantations, especially in the lower valley slopes near water, and often in deep shade.  Given its ability to live happily in such forests, this species has a secure future in Japan.

The flowers are born in loose clusters, are very small (5-7 mm), and star shaped.  They just precede the new growth, starting in March and continuing through April.  The four (sometimes five) petals are maroon in color with a green center and sometimes are edged in white.  While they are too small to be considered showy, each is very pretty when viewed closely.  This plant is dioecious, that is, there are separate sex plants with male flowers and female flowers.  The oblong fruits that grow only on the female plants start out bright green and turn deep orange-red in winter.  Wildlife seems to disdain these, so they last well into spring before falling to the ground.

Aucuba japonica is found in the warmer regions of Japan as far north on Honshu as Miyagi and Yamagata Prefectures, and southward to Shikoku, Kyushu, and the southern islands.  It also grows in South Korea, Taiwan, and southeast China.  It is found in warm temperate to subtropical moist forests on mountains as an under story tree or shrub.  In Japan it commonly grows in hinoki (Chamaecyparis) and sugi (Cryptomeria) plantation forests as well. It is usually found at lower elevations, less than 500 meters, particularly along streams and wet seepy slopes.  Plants can occur singly in a woodland, but are most commonly seen in large, dense groups.
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Native to the wet forests of subtropical and tropical Asia, the camphor tree, Cinnamomum camphora, has been planted across the world’s warm temperate, subtropical, and tropical regions.  It is a tree of many faces – a stately forest giant in its native range, a rampant pest in eastern Australia, a source of spice in south Asian cuisine, a shade tree in Florida, a natural pesticide – the list goes on.  Its defining feature is the essential oil that can be extracted from its tissues and the cocktail of aromatic chemicals that give the oil its pungent, fresh odor.  Of these, camphor is the star – a highly aromatic terpene like chemical.

Cinnamomum camphora is a massive broad leaved evergreen tree that grows to 30 m tall (some sources report even higher) with a broad sweeping crown.  The spread of the tree can equal its height in field grown specimens, truly a breath-taking thing to see.  The trunk can grow to over two meters in diameter with the top end reported to be 8 meters. The largest I’ve seen was around 3 meters.

The leaves are dark to light green and glossy with lighter colored veins, 8-15 cm long and 3-7 cm wide.  Leaf shape is highly variable, sometimes ovate and some elongate, each growing in alternating positions on twigs.  The bark is rough and brownish-grey.  The tiny star shaped flowers are in lose clusters in mid spring and are white.  By November the dark blue berries ripen and are quite small, less than 1 cm across.  The new foliage in spring flushes purple-red, then turns brilliant electric green, and finally maturing rich green.  During new growth and just after (April and May) the previous year’s leaves fall, and are a lovely orange-red.

Camphor trees are found throughout the warmer regions of Japan as far north on Honshu in the Kanto region, Shikoku, Kyushu, and the islands southward to Okinawa.  Beyond Japan’s borders it is found in much of east Asia including China, Taiwan, Korea, Indochina, and India.  In Japan it grows in warm temperate and subtropical forests on mountains and further north in coastal forests.  It grows to 800 meters elevation in the south, then found at progressively lower elevations northward, and finally restricted to coastal low forest in central Honshu.  It can be dominant in some forests, but most often is mixed in with other broad leaved trees.

This is another member of the Laurel Family (Lauraceae), hence its other name, camphor laurel tree.  In the broad leaf evergreen forests of southern Japan this species sticks out due to its incredible size and mass.  It once was used in the production of camphor oil, especially before WWII.  It has been grown as a specimen tree in the warmer parts of the world, and in certain regions it has become an invasive pest.  In Japan it is well behaved, forming a lovely spreading tree in time.

The warm temperate and subtropical forests of Japan are home to one of the world’s largest bay trees, Machilus thunbergii.  Massive specimens are found throughout Japan, at temples and shrines, public parks, and of course in their native forests.  This tree is one of southern Japan’s most impressive broad leaf hardwoods, outdone only by the camphor tree, Cinnamomum camphora.

Machilus thunbergii is a massive broad leaved evergreen tree with the potential to grow 30 m tall.  The trunk itself can grow to over a meter in diameter. The leaves are dark green and shiny, 8-15 cm long and 3-7 cm wide.  In the spring they flush brilliant lime green or sometimes crimson red.  These grow alternating on the branches and contain a mucus like sap, one identifying characteristic for this species. The bark is rough and brownish-grey, and breaks off in chunks.  The star shaped flowers are born in round clusters in mid spring, and are bright green.  They are quickly followed by blue-black berries in early summer

The most notable features of this giant are its large evergreen leaves, broad sweeping crown, lovely tiered branching, and its shear mass.  The overall impression one gets is of a tropical rain forest tree, particularly when covered in epiphytic ferns. which it often is.  In places where old growth forest still exists, this tree stands out as one of the more impressive species, and indeed is the second most massive broad leaf hardwood next to the camphor tree, Cinnamomom camphora, in Japan’s southern forests.

In Japan this tree is found in warm temperate forests in the mountains of Kyushu, Shikoku, and Honshu.  On Yaku Island just south of Kyushu it grows as high as 1200 meters up mountains, but is found in progressively lower altitudes further north, even into southern Nagano Prefecture on Honshu.   It reaches its northern limit in southern Aomori Prefecture along the Sea of Japan coast, and to southern Iwate Prefecture on the Pacific side.  In these northern areas it is limited to seaside forests, where it is a much smaller tree in all respects.  It is also found throughout Japan’s southern islands to Okinawa and beyond to Taiwan, South Korea, China, and the Philippines.
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Japan’s forests are home to a massive tree species – this country’s answer to a redwood.  It is the famous Japanese cedar, Cyrptomeria japonica, but better known as sugi in Japan.  This tree is both beloved and at the same time nearly despised in modern Japan for reasons this article will make clear.

Cryptomeria japonica var. japonica (hereafter called simply C. japonica) is a massive evergreen coniferous tree reaching 50 meters or more high – some are said to be 70 meters, an almost unimaginable height for these typhoon swept islands.  Likewise, its trunk girth is gargantuan, up to 10 meters or more in some specimens with the limit being around 16 meters.  The bark is reddish brown to silvery, growing in strips.  In young trees these can flake off, but older trees have more compact bark that is thicker in substance.

The branches grow in a whorl up the trunk and tend to hang down a bit.  Young trees are nearly conical in shape, but old trees have irregular branching, more pendulous branches, and tend to be rounded at the top.  It is not uncommon to see multi-trunked specimens and ones that have saddle like branches – all the product of storm damage in their past.  In old specimens the lower trunk can be branch-less for 10 or more meters.

Japanese cedar leaves are light green to bluish green, needle like in appearance and either hang down or grow upward in loose clusters.  They tend to break off in large pieces when they fall rather than falling apart on the tree.  As a consequence, the forest floor is littered with their leaf clusters and small branches, sometimes to a depth of 15 cm or more.  Their foliage commonly “bronzes” in cold weather, so sugi forests can look red brown in the winter months.

The pollen cones (male) and seed cones (female) are born separately, but on the same tree (monoecious habit).  The yellow-brown pollen cones grow in bunches on the outermost twigs and are roughly conical shaped and are only a centimeter or so long each.  The seed cones start out growing bright green and eventually turn a rich brown at maturity.  The male cones release their pollen starting in February in Kyushu and perhaps until May further north.  In pollen season the air can literally be filled with sugi pollen, much like a dust storm.

C. japonica ranges throughout the warmer parts of Japan.  The variety sinensis is found in China.  No variety is listed as native to Korea, which is surprising given that Korea, China, and Japan have been connected many times in past glacial periods.  It prefers wet to moist woodlands, along mountain streams and seepage slopes, but also can be found on exposed ridge-lines, from 0 to 1000+ meters elevation.  Trees can be in mixed stands with other conifers or most often with broad leaf trees, both deciduous and evergreen.  Pure stands are known to occur, but this may be an artifact of human planting in the distant past.

This is one of the most distinctive Japanese trees.  For one thing, it is the tallest and most massive tree species in Japan being a close relative to redwoods and sequoias.  Culturally it is also significant in several ways. It is the national tree of Japan and large specimens are often seen at temples.  Many of these are considered to house a god (kami).  It also is one of the most important timber species in the country, especially in the south.  Sugi plantations can be seen on almost any mountain here.  After WWII a massive program was instituted to reforest Japan’s mountainsides. Both sugi and hinoki (Chamaecyparis obtusa) were widely planted in this effort.  A negative effect that was not considered was that during pollen season people would end up suffering, and suffer they do.  In late winter and early spring millions of people have to endure weeks of hay-fever brought on by the clouds of sugi and hinoki pollen coming off the mountainsides.  Since Japanese cedar is an important lumber tree, it is likely that plantation forests will continue to be maintained into future, despite this problem.
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