Zelkova serrata

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Zelkova serrata
Zelkova serrata Noma keyaki01.jpg
"Noma Keyaki", a 1,000-year-old keyaki in Nose near Osaka in Japan, 25 m tall, 11.95 m trunk circumference; second-largest known specimen [1]
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Rosales
Family: Ulmaceae
Genus: Zelkova
Species:
Z. serrata
Binomial name
Zelkova serrata

Zelkova serrata (Japanese zelkova, Japanese elm [2] or keyaki; Japanese : 欅 (ケヤキ) keyaki /槻 (ツキ) tsuki; Chinese :榉树/櫸樹 jǔshù; Korean : 느티나무 neutinamu) is a species of the genus Zelkova native to Japan, Korea, eastern China and Taiwan. [3] [4] It is often grown as an ornamental tree, and used in bonsai. There are two varieties, Zelkova serrata var. serrata in Japan and mainland eastern Asia, and Zelkova serrata var. tarokoensis (Hayata) Li on Taiwan which differs from the type in its smaller leaves with less deeply cut serration on the margins. [4]

Contents

Description

Foliage and flowers in spring Zelkova serrata5.jpg
Foliage and flowers in spring
Bark of mature Japanese zelkova Bark of Zelkova serrata.jpg
Bark of mature Japanese zelkova

Zelkova serrata is a medium-sized deciduous tree usually growing to 30 m (98 ft) tall. It 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. [5]

It has alternately arranged leaves growing to 5 cm long and broad. The leaves themselves are simple and ovate to oblong-ovate with serrated or crenate margins, to which the tree owes its specific epithet serrata. The leaves are acuminate or apiculate, rounded or subcordate at the base, and contain 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, changing to yellows, oranges and reds in autumn. The petioles are 2–5 mm (116316 in) long. [6]

Zelkova serrata is monoecious. It develops flowers in spring with the leaves. Buds are ovoid, acutish, with many imbricate, dark brown scales. [5] 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 lower 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 maturing to brown, subsessile and 2.5 to 3.5 mm (332 to 18 in) in diameter.

To identify Zelkova serrata, one would look for a short main trunk, low branching and a vase-shaped habit. The 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. The branchlets are brownish-purple to brown.

Cultivation

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 5 °C (41 °F) for 60 days. [5] 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. [7] Zelkova serrata also shows good resistance to elm leaf beetle and Japanese beetle.

Cultivation and uses

Zelkova serrata bonsai from the United States National Arboretum Japanese Zelkova, 1895-2007.jpg
Zelkova serrata bonsai from the United States National Arboretum

Zelkova serrata 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. It is also commonly used for bonsai; its attractive shape and colors make it a popular choice for the art. [3] [4] 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. [4] Recently, it has been planted as a "street tree" in New York City. [8] In the UK it has gained the Royal Horticultural Society's Award of Garden Merit. [9]

Numerous cultivars have been selected, including:

It has also hybridised with Zelkova carpinifolia in Europe, the hybrid being named Zelkova × verschaffeltii. [4]

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, Takatsuki City and more.

According to data investigated by Korea Forest Service in 1989, the largest number of trees over 500 years old were specimens of Zelkova serrata, among which more than ten have been registered as Natural Monuments of Korea. [11]

Suppliers

Within the United Kingdom, the Royal Horticultural Society's Plantfinder currently lists 38 suppliers for the pure species and associated varieties. [12]

Related Research Articles

<i>Serissa</i>

Serissa is a genus of flowering plants in the family Rubiaceae, containing only one species, Serissa japonica. It is native to open sub-tropical woodlands and wet meadows in southeast Asia, from India, and China to Japan. It is commonly called the snowrose, tree of a thousand stars, or Japanese boxthorn; and was formerly called Serissa foetida. 'Foetida' referres to the unpleasant, vomit-like, odour that the trees give off if their leaves are pruned or bruised. Snowrose and tree of a thousand stars are different cultivars. The only method of differentiating is measuring the difference in the shape and size of the flowers produced.

<i>Cercis canadensis</i> Species of tree

Cercis canadensis, the eastern redbud, is a large deciduous shrub or small tree, native to eastern North America from southern Michigan south to central Mexico, east to New Jersey. Species thrive as far west as California and as far north as southern Ontario, roughly corresponding to USDA hardiness zone 6b. It is the state tree of Oklahoma.

<i>Zelkova</i>

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 (115 ft) tall. The bark is smooth, dark brown. Unlike the elms, the branchlets are never corky or winged. The leaves are alternate, with serrated margins, and a symmetrical base to the leaf blade. The leaves are in two distinct rows; they have pinnate venation and each vein extends to the leaf margin, where it terminates in a tooth. There are two stipules at each node, though these are caducous, leaving a pair of scars at the leaf base. Zelkova is polygamous. Staminate flowers are clustered in the lower leaf axils of young branchlets; the perianth is campanulate, with four to six lobes, and the stamens are short. Pistillate and hermaphrodite flowers are solitary, or rarely in clusters of two to four, in the upper leaf axils of young branchlets. The fruit is a dry, nut-like drupe with a dorsal keel, produced singly in the leaf axils. The perianth and stigma are persistent.

<i>Hibiscus syriacus</i> Species of flowering plant

Hibiscus syriacus is a species of flowering plant in the mallow family, Malvaceae. It is native to south-central and southeast China, but widely introduced elsewhere, including much of Asia. It was given the epithet syriacus because it had been collected from gardens in Syria. Common names include the Korean rose, rose of Sharon, Syrian ketmia, shrub althea, rose mallow. It is the national flower of South Korea and is mentioned in the South Korean national anthem.

<i>Chamaecyparis pisifera</i> Species of conifer

Chamaecyparis pisifera is a species of false cypress, native to central and southern Japan, on the islands of Honshū and Kyūshū.

<i>Ilex crenata</i> Species of holly

Ilex crenata, the Japanese holly or box-leaved holly is a species of flowering plant in the family Aquifoliaceae, native to eastern China, Japan, Korea, Taiwan, and Sakhalin.

<i>Cornus sericea</i> Species of flowering plant

Cornus sericea, syn. C. stolonifera, Swida sericea, red osier or red-osier dogwood, is a species of flowering plant in the family Cornaceae, native throughout northern and western North America from Alaska east to Newfoundland, south to Durango and Nuevo León in the west, and Illinois and Virginia in the east. It has sometimes been considered a synonym of the Asian species Cornus alba. Other names include red brush, red willow, redstem dogwood, redtwig dogwood, red-rood, American dogwood, creek dogwood, and western dogwood.

<i>Schefflera arboricola</i>

Schefflera arboricola is a flowering plant in the family Araliaceae, native to Taiwan as well as Hainan. Its common name is dwarf umbrella tree, as it resembles a smaller version of the umbrella tree, Schefflera actinophylla.

<i>Larix kaempferi</i> Species of conifer in the pine family Pinaceae

Larix kaempferi, the Japanese larch or karamatsu (唐松) in Japanese, is a species of larch native to Japan, in the mountains of Chūbu and Kantō regions in central Honshū.

<i>Cornus alba</i>

Cornus alba, the red-barked, white or Siberian dogwood, is a species of flowering plant in the family Cornaceae, native to Siberia, northern China and Korea. It is a large deciduous surculose (suckering) shrub that can be grown as a small tree. As a popular ornamental used in landscaping its notable features include the red stems in fall (autumn) through late winter, the brightest winter bark of any cornus; and the variegated foliage in some cultivars, such as C. alba 'Elegantissima', in which the discreet flat whitish flower clusters are almost lost in the variegated texture and dappled light. C. alba can grow to 3 m (10 ft) high, but variegated forms are less vigorous. For the brightest winter bark, young shoots are encouraged by cutting to the ground some older stems at the end of the winter, before leaves are open. The oval fruits are white, sometimes tinted blue.

<i>Cladrastis kentukea</i> Species of legume

Cladrastis kentukea, the Kentucky yellowwood or American yellowwood, is a species of Cladrastis native to the Southeastern United States, with a restricted range from western North Carolina west to eastern Oklahoma, and from southern Missouri and Indiana south to central Alabama. Also the tree is sometimes called Virgilia.

<i>Salix integra</i> Species of willow

Salix integra is a species of willow native to northeastern China, Japan, Korea and Primorsky Krai in the far southeast of Russia.

<i>Zelkova carpinifolia</i> Species of tree

Zelkova carpinifolia, known as Caucasian zelkova, Caucasian elm or just zelkova, is a species of Zelkova, native to the Caucasus, Kaçkar, and Alborz mountains in the extreme southeast of Europe and southwest Asia.

<i>Stewartia pseudocamellia</i>

Stewartia pseudocamellia, also known as Korean stewartia, Japanese stewartia, or deciduous camellia, is a species of flowering plant in the family Theaceae, native to Japan and Korea.

<i>Acer rufinerve</i> Species of maple

Acer rufinerve, the grey-budded snake-bark-maple, redvein maple or Honshū maple, is a species of tree in the snakebark maple group, related to Acer capillipes. It is native to mountain forests of Japan, on Honshū, Kyūshū and Shikoku.

<i>Ulmus minor</i> Argenteo-Variegata

The Field Elm cultivar Ulmus minor 'Argenteo-Variegata' or simply 'Variegata', known in Australasia and North America as Silver Elm or Tartan Elm, is said to have been cultivated in France from 1772. Green noted that variegated forms of Field Elm "arise frequently, and several clones may have been known under this name". Dumont de Courset (1802) listed an U. campestris var. glabra variegata, Loudon (1838) an U. nitens var. variegata, and Wesmael (1863) an U. campestris var. nuda microphylla variegata.

<i>Ilex latifolia</i> Species of holly

Ilex latifolia is a species of holly, native to southern Japan and eastern and southern China, growing in broadleaf forests at altitudes of 200–1,500 m.

<i>Ulmus parvifolia</i> Species of tree

Ulmus parvifolia, commonly known as the Chinese elm or lacebark elm, is a species native to eastern Asia, including mainland China, Taiwan, Japan, North Korea, South Korea and Vietnam. It has been described as "one of the most splendid elms, having the poise of a graceful Nothofagus".

<i>Hydrangea serrata</i> Species of flowering plant in the family Hydrangeaceae

Hydrangea serrata is a species of flowering plant in the family Hydrangeaceae, native to mountainous regions of Korea and Japan. Common names include mountain hydrangea and tea of heaven. Growing to 1.2 m (4 ft) tall and broad, it is a deciduous shrub with oval leaves and panicles of blue and pink flowers in summer and autumn (fall). It is widely cultivated as an attractive ornamental shrub throughout the world in areas with suitable climate and soil.

<i>Acer palmatum</i> Species of maple

Acer palmatum, commonly known as Japanese maple, palmate maple, or smooth Japanese maple, is a species of woody plant native to Japan, Korea, China, eastern Mongolia, and southeast Russia. Many different cultivars of this maple have been selected and they are grown worldwide for their large variety of attractive forms, leaf shapes, and spectacular colors.

References

  1. Osaka Toyono County: Noma Keyaki (in Japanese; google translation)
  2. BSBI List 2007 (xls). Botanical Society of Britain and Ireland. Archived from the original (xls) on 2015-06-26. Retrieved 2014-10-17.
  3. 1 2 Flora of China: Zelkova serrata
  4. 1 2 3 4 5 Andrews, S. (1994). Tree of the year: Zelkova. Int. Dendrol. Soc. Yearbook 1993: 11-30.
  5. 1 2 3 Rehder, Alfred. Manual of Cultivated Trees and Shrubs. 2. New York: The Macmillan Company, 1949. Print.
  6. Dirr, Michael A. Manual of Woody Landscape Plants: Their Identification, Ornamental Characteristics, Culture, Propagation and Uses. 3. Champaign: Stipes Publishing Company, 1975. Print.
  7. "#820 Zelkova Serrata." Floridata. 01 25 2004. 4 May 2009 .
  8. New York City Parks Street Tree List
  9. "Zelkova serrata". RHS. Retrieved 5 March 2021.
  10. Zelkova serrata 'Green Vase' photos
  11. Lee, chang-bok (1989). 검팽나무와 노란팽나무. 《자생식물》 16: 86. Accessed on October 9, 2013
  12. Plantfinder