Zelkova serrata
Encyclopedia
Zelkova serrata is a species of Zelkova
native to Japan
, Korea
, eastern China
, and Taiwan
. It is often grown as an ornamental tree, and used in bonsai
.
In summer, this tree has alternately arranged deciduous leaves. The leaves themselves are simple and ovate to oblong-ovate with serrated or crenate margins, to which the tree owes its species name “Serrata”. The leaves are acuminate or apiculate, rounded or subcordate at the base and contain about 8-14 pairs of veins. The leaves are rough on top and glabrous or nearly glabrous on the underside. They are green to dark green in spring and throughout the summer, though they change color in the autumn to a various assortment of yellows, oranges and reds. Leaves are 3-5 cm (1-2 in) long and 2-5 cm (0.8-2 inches) wide, on shoots that are approximately 12-13 cm (5 in) long. Petioles are 2-5 mm long.
Zelkova serrata develops monoecious flowers in spring with the leaves. Buds are ovoid, acutish, with many imbricate, dark brown scales. They diverge at a 45 degree angle from the stem. The staminate flowers are shortly pedicellate and approximately 3mm in diameter, clustered in the axils of the lowers leaves. The pistillate flowers are solitary or few in axils of the upper leaves, sessile and usually about 1.5 mm in diameter. The flowers are yellow-green, not showy, and occur in tight groups along new stems. They give rise to small, ovate, wingless drupes that ripen in late summer to autumn. The drupe is green though matures to a brown color, subsessile and 2.5 to 3.5 mm in diameter.
To identify Zelkova serrata, one would look for a short main trunk, low branching and a vase shaped habit. Its twigs are slender with small, dark conical buds in a zigzag pattern. The branches are usually glabrous. The bark is grayish white to grayish brown and either smooth with lenticels or exfoliating in patches to reveal orange inner bark. Branchlets are brownish purple to brown.
.
There are two varieties
, Zelkova serrata var. serrata in Japan and mainland eastern Asia, and Zelkova serrata var. tarokoensis (Hayata) Li on Taiwan; the latter differs from the type in its smaller leaves with less deeply cut serration on the margins.
It is often grown as an ornamental tree, both in its native area and in Europe and North America. The first cultivation outside of Asia was by Philipp Franz von Siebold
, who introduced it to the Netherlands
in 1830. Recently, it has been planted as a "street tree" in New York City
Numerous cultivar
s have been selected, including 'Fuiri Keaki' (variegated
leaves), 'Goblin' (dwarf), 'Goshiki' (variegated leaves), 'Green Vase' (tall, narrow crown), 'Green Veil' (pendulous branchlets), 'Iruma Sango' (fastigiate), 'Nire Keaki' (semi-dwarf), 'Pulverulenta' (variegated leaves), 'Spring Grove' (upright crown), 'Variegata' (variegated leaves), 'Village Green' (grows more rapidly than ordinary seedlings and develops a straight smooth trunk. Hardier than trees of Japanese origin photos), 'Variegata' (weak growing, small leaved form with a narrow white rim around the margin of the leaf),'Parkview' (selection with good vase-shape, size similar to species) and 'Urban Ruby' (red autumn colour). It has also hybridised with Zelkova carpinifolia
in Europe, the hybrid being named Zelkova × verschaffeltii
.
Keyaki wood
is valued in Japan and used often for furniture, such as tansu
, as well as being considered the ideal wood for the creation of taiko
drums.
The tree is a symbol of a number of Japanese cities and prefectures: Saitama Prefecture
, Miyagi Prefecture, Fukushima Prefecture, Fukushima-shi, Abiko-shi, Tachikawa-shi, Yokohama-shi, Machida City
in Tokyo Metropolis District
and more.
Zelkova
Zelkova is a genus of six species of deciduous trees in the elm family Ulmaceae, native to southern Europe, and southwest and eastern Asia. They vary in size from shrubs to large trees up to 35 m tall . The leaves are alternate, with serrated margins, and a symmetrical base to the leaf blade...
native to Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, Korea
Korea
Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...
, eastern China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, and Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
. It is often grown as an ornamental tree, and used in bonsai
Bonsai
is a Japanese art form using miniature trees grown in containers. Similar practices exist in other cultures, including the Chinese tradition of penjing from which the art originated, and the miniature living landscapes of Vietnamese hòn non bộ...
.
Description
Zelkova serrata is a medium sized deciduous tree usually growing to 30 meters (100 ft) tall. This tree is characterized by a short trunk dividing into many upright and erect spreading stems forming a broad, round topped head. The tree grows rapidly when young though the growth rate slows to medium upon middle age and maturity.In summer, this tree has alternately arranged deciduous leaves. The leaves themselves are simple and ovate to oblong-ovate with serrated or crenate margins, to which the tree owes its species name “Serrata”. The leaves are acuminate or apiculate, rounded or subcordate at the base and contain about 8-14 pairs of veins. The leaves are rough on top and glabrous or nearly glabrous on the underside. They are green to dark green in spring and throughout the summer, though they change color in the autumn to a various assortment of yellows, oranges and reds. Leaves are 3-5 cm (1-2 in) long and 2-5 cm (0.8-2 inches) wide, on shoots that are approximately 12-13 cm (5 in) long. Petioles are 2-5 mm long.
Zelkova serrata develops monoecious flowers in spring with the leaves. Buds are ovoid, acutish, with many imbricate, dark brown scales. They diverge at a 45 degree angle from the stem. The staminate flowers are shortly pedicellate and approximately 3mm in diameter, clustered in the axils of the lowers leaves. The pistillate flowers are solitary or few in axils of the upper leaves, sessile and usually about 1.5 mm in diameter. The flowers are yellow-green, not showy, and occur in tight groups along new stems. They give rise to small, ovate, wingless drupes that ripen in late summer to autumn. The drupe is green though matures to a brown color, subsessile and 2.5 to 3.5 mm in diameter.
To identify Zelkova serrata, one would look for a short main trunk, low branching and a vase shaped habit. Its twigs are slender with small, dark conical buds in a zigzag pattern. The branches are usually glabrous. The bark is grayish white to grayish brown and either smooth with lenticels or exfoliating in patches to reveal orange inner bark. Branchlets are brownish purple to brown.
Environmental needs
This tree requires full to partial sun and prefers moist, well drained soils. A fertilizer rich in potassium and nitrogen encourages new vegetation and floral buds. It is adaptable and tolerant of heat, little water, nutrient poor soils and various pH. It should be periodically thinned to allow light into the inner canopy. Zelkova serrata is propagated by seeds, rooted stem cuttings and grafting. The seeds germinate without pretreatment, though the percentage is better when stratified at 41 degrees F for 60 days. Because germination requires stratification, the seed is best sown early in the year. To ensure survival it may be necessary to pot the tree and grow it in a greenhouse for its first winter. It may be reintroduced into its permanent habitat after the final frost.Threats
The threats to this tree include colder temperature, which often result in twig dieback. It is highly resistant to Dutch Elm Disease, which makes it a good replacement tree for American Elm. Zelkova serrata is similar in appearance to the elms, though may be distinguished by its unwinged fruit and leaves which are symmetrical rather than uneven at their base. Zelkova serrata also shows good resistance to elm leaf beetle and Japanese beetleJapanese beetle
The beetle species Popillia japonica is commonly known as the Japanese beetle. It is about long and wide, with iridescent copper-colored elytra and green thorax and head...
.
Variants
Zelkova serrata does have properties useful to man, though mostly superficial. It is planted as a lawn or park tree for its attractive bark, leaf color and vase shape. It provides good shade and has an easy fall cleanup. It is easy to transport, and often available in burlap form. Zelkova serrata is also commonly used for bonsai; its attractive shape and colors make it a popular choice for the art.There are two varieties
Variety (biology)
In botanical nomenclature, variety is a taxonomic rank below that of species: as such, it gets a three-part infraspecific name....
, Zelkova serrata var. serrata in Japan and mainland eastern Asia, and Zelkova serrata var. tarokoensis (Hayata) Li on Taiwan; the latter differs from the type in its smaller leaves with less deeply cut serration on the margins.
Cultivation and uses
Philipp Franz von Siebold
Philipp Franz Balthasar von Siebold was a German physician and traveller. He was the first European to teach Western medicine in Japan...
, who introduced it to the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
in 1830. Recently, it has been planted as a "street tree" in New York City
Numerous cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...
s have been selected, including 'Fuiri Keaki' (variegated
Variegation
Variegation is the appearance of differently coloured zones in the leaves, and sometimes the stems, of plants. This may be due to a number of causes...
leaves), 'Goblin' (dwarf), 'Goshiki' (variegated leaves), 'Green Vase' (tall, narrow crown), 'Green Veil' (pendulous branchlets), 'Iruma Sango' (fastigiate), 'Nire Keaki' (semi-dwarf), 'Pulverulenta' (variegated leaves), 'Spring Grove' (upright crown), 'Variegata' (variegated leaves), 'Village Green' (grows more rapidly than ordinary seedlings and develops a straight smooth trunk. Hardier than trees of Japanese origin photos), 'Variegata' (weak growing, small leaved form with a narrow white rim around the margin of the leaf),'Parkview' (selection with good vase-shape, size similar to species) and 'Urban Ruby' (red autumn colour). It has also hybridised with Zelkova carpinifolia
Zelkova carpinifolia
Zelkova carpinifolia is a species of Zelkova, native to the Caucasus, Kaçkar, and Alborz mountains in the extreme southeast of Europe and southwest Asia....
in Europe, the hybrid being named Zelkova × verschaffeltii
Zelkova × verschaffeltii
Zelkova × verschaffeltii is a zelkova cultivar of hybrid origin. It was originally described in 1892 by Leopold Dippel from a cultivated plant as Zelkova japonica var. verschaffeltii, suggesting an eastern Asian origin for it...
.
Keyaki wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
is valued in Japan and used often for furniture, such as tansu
Tansu
Tansu is the word for chest, chest of drawers or cupboard in Japanese. It is often used in the West to refer to traditional Japanese chests, handcrafted and made of fine woods, such as Hinoki , Keyaki , Kuri , Sugi and Kiri .Many collectors focus on finding antique Tansu...
, as well as being considered the ideal wood for the creation of taiko
Taiko
means "drum" in Japanese . Outside Japan, the word is often used to refer to any of the various Japanese drums and to the relatively recent art-form of ensemble taiko drumming...
drums.
The tree is a symbol of a number of Japanese cities and prefectures: Saitama Prefecture
Saitama Prefecture
is a prefecture of Japan located in the Kantō region of the island of Honshu. The capital is the city of Saitama.This prefecture is part of the Greater Tokyo Area, and most of Saitama's cities can be described as suburbs of Tokyo, to which a large amount of residents commute each day.- History...
, Miyagi Prefecture, Fukushima Prefecture, Fukushima-shi, Abiko-shi, Tachikawa-shi, Yokohama-shi, Machida City
Machida, Tokyo
is a city located in the western part of the greater metropolis of Tokyo, Japan. The city was founded on February 1, 1958.As of October 1, 2010, the city has an estimated population of 424,669 and a population density of 5,928.65 persons per km². The total area is 71.63 km²...
in Tokyo Metropolis District
Tokyo
, ; officially , is one of the 47 prefectures of Japan. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of Japan. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family...
and more.
Suppliers
Within the United Kingdom, the Royal Horticultural Society's Plantfinder http://apps.rhs.org.uk/rhsplantfinder/ currently lists 38 suppliers for the pure species and associated varieties.External links
- "Zelkova Serrata." The Ohio State University. 4 May 2009.
- "Family Ulmaceae." Zipcodezoo. 05 23 2009. 4 May 2009.