Zelkova serrata

Zelkova serrata
"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]
Conservation status
Near Threatened  (IUCN 3.1 )
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Rosales
Family:	Ulmaceae
Genus:	Zelkova
Species:	Z. serrata
Binomial name
Zelkova serrata ( Makino

Zelkova serrata (Japanese zelkova, Japanese elm,

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 (2 in) long and broad. The leaves themselves are simple and

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.

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.^{[citation needed]}

The tree is prone to fungus Griphosphaerioma zelkovicola which was first observed in Japan on the bark of Zelkova serrata trees in 2003.^[8]

Cultivation

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

Within the United Kingdom, the Royal Horticultural Society's Plantfinder currently lists 38 suppliers for the pure species and associated varieties.[11]

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.^{[citation needed]}

Numerous cultivars have been selected, including:

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

Uses

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.

In culture

In Korea, Zelkova serrata has been considered a symbol of protection for villages since ancient times, and can still be found planted at central points in cities, towns and villages around the country.^[13] The trees often stand next to small pavilions, serving both as shaded informal gathering points, and spaces for traditional rituals and ceremonies involving prayer and offerings to the tree.^[14] The oldest of these trees are estimated to be in excess of 1,000 years in age, and are protected as natural monuments by Korean law.^[15] In 2013, the Korea Forest Research Institute announced a project to clone the zelkova, pine, and ginkgo trees that are identified as natural monuments, so their lineage will not be lost in case of disaster or death due to age.^[16]

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.^[17]

The tree is a symbol of a number of Japanese cities and prefectures:

Gallery

• 
  Autumn colour, November, Saitama Prefecture, Japan
• 
  Trees lining an avenue in Sendai, Japan
• 
  Morton Arboretum
  acc. 10-54-1
• 
  A Japanese Sendai-dansu for kimono made from keyaki wood
• 
  Hyogo

  in the winter
• 
  An example of a mature tree

References

External links

Wikimedia Commons has media related to Zelkova serrata.

• "Zelkova Serrata." The Ohio State University. 4 May 2009.