The cherry blossom, or sakura, is the flower of trees in Prunus subgenus Cerasus. Sakura usually refers to flowers of ornamental cherry trees, such as cultivars of Prunus serrulata, not trees grown for their fruitThe history and cultural symbolism of both the seven wild species and the hundreds of forms known for centuries as sato-zakura, or garden cherries and information about growing and propagating is found in (although these also have blossoms). Cherry blossoms have been described as having a vanilla-like smell, which is mainly attributed to coumarin.
Wild species of cherry tree are widely distributed, mainly in the Northern Hemisphere. They are common in East Asia, especially in Japan, where they have been cultivated, producing many varieties.
Most of the ornamental cherry trees planted in parks and other places for viewing are cultivars developed for ornamental purposes from various wild species. In order to create a cultivar suitable for viewing, a wild species with characteristics suitable for viewing is needed. Prunus speciosa (Oshima cherry), which is endemic to Japan, produces many large flowers, is fragrant, easily mutates into double flowers and grows rapidly. As a result, various cultivars, known as the Cerasus Sato-zakura Group, have been produced since the 14th century and continue to contribute greatly to the development of hanami (flower viewing) culture. From the modern period, cultivars are mainly propagated by grafting, which quickly produces cherry trees with the same genetic characteristics as the original individuals, and which are excellent to look at.
The Japanese word can mean either the tree or its flowers (see ). The cherry blossom is considered the national flower of Japan, and is central to the custom of hanami.
Sakura trees are often called Japanese cherry in English. (This is also a common name for Prunus serrulata.) The cultivation of ornamental cherry trees began to spread in Europe and the United States in the early 20th century, particularly after Japan presented trees to the United States as a token of friendship in 1912. British plant collector Collingwood Ingram conducted important studies of Japanese cherry trees after the First World War.
Classification
Classifying cherry trees is often confusing, since they are relatively prone to mutation and have diverse flowers and characteristics, and many varieties (a sub-classification of species), hybrids between species, and cultivars exist. Researchers have assigned different scientific names to the same type of cherry tree throughout different periods.
In Europe and North America, ornamental cherry trees are classified under the subgenus Cerasus ("true cherries"), within the genus Prunus. Cerasus consists of about 100 species of cherry tree, but does not include bush cherries, bird cherries, or cherry laurels (other non-Cerasus species in Prunus are plums, peaches, apricots, and almonds). Cerasus was originally named as a genus in 1700 by de Tournefort. In 1753, Linnaeus combined it with several other groupings to form a larger Prunus genus. Cerasus was later converted into a section and then a subgenus, this system becoming widely accepted, but some botanists resurrected it as a genus instead. In China and Russia, where there are many more wild cherry species than in Europe, Cerasus continues to be used as a genus.
In Japan, ornamental cherry trees were traditionally classified in the genus Prunus, as in Europe and North America, but after a 1992 paper by Hideaki Ohba of the University of Tokyo, classification in the genus Cerasus became more common. This means that (for example) the scientific name Cerasus incisa is now used in Japan instead of Prunus incisa.
A culture of plum blossom viewing has existed in mainland China since ancient times, and although cherry trees have many wild species, most of them had small flowers, and the distribution of wild cherry trees with large flowers suitable for cherry blossom viewing was limited. In Europe and North America, there were few cherry species with characteristics suitable for cherry blossom viewing. In Japan, on the other hand, the Prunus speciosa (Oshima cherry) and Prunus jamasakura (Yamazakura), which have large flowers suitable for cherry blossom viewing and tend to grow into large trees, were distributed over a fairly large area of the country and were close to people's living areas. The development of cherry blossom viewing, and the production of cultivars, is therefore considered to have taken place primarily in Japan.
Because cherry trees have mutable traits, many cultivars have been created for cherry blossom viewing, especially in Japan. Since the Heian period, the Japanese have produced cultivars by selecting superior or mutant trees from among the natural crossings of wild cherry trees. They were also produced by crossing trees artificially and then breeding them by grafting and cutting. Oshima, Yamazakura, Prunus pendula f. ascendens (syn, Prunus itosakura, Edo higan), and other varieties which grow naturally in Japan, mutate easily. The Oshima cherry, which is an endemic species in Japan, tends to mutate into a double-flowered tree, grows quickly, has many large flowers, and has a strong fragrance. Due to these favorable characteristics, the Oshima cherry has been used as a base for many Sakura cultivars (called the Sato-zakura Group). Two such cultivars are the Yoshino cherry and Kanzan; Yoshino cherries are actively planted in Asian countries, and Kanzan is actively planted in Western countries.
Hanami: Flower viewing in Japan
is the many centuries-old practice of holding feasts or parties under blooming sakura ( or ; or ) or (; ) trees. During the Nara period (710–794), when the custom is said to have begun, it was blossoms that people admired. By the Heian period (794–1185), however, cherry blossoms were attracting more attention, and was synonymous with . From then on, in both and haiku, meant "cherry blossoms," as implied by one of Izumi Shikibu's poems. The custom was originally limited to the elite of the Imperial Court but soon spread to samurai society and, by the Edo period, to the common people as well. Tokugawa Yoshimune planted areas of cherry blossom trees to encourage this. Under the trees, people held cheerful feasts where they ate, and drank sake.
Since a book written in the Heian period mentions , one of the cultivars with pendulous branches, Prunus itosakura 'Pendula' (Sidare-zakura) is considered the oldest cultivar in Japan. In the Kamakura period, when the population increased in the southern Kantō region, the Oshima cherry, which originated in Izu Oshima Island, was brought to Honshu and cultivated there; it then made its way to the capital, Kyoto. The Sato-zakura Group first appeared during the Muromachi period.
Prunus itosakura (syn. Prunus subhirtella, Edo higan) is a wild species that grows slowly. However, it has the longest life span among cherry trees and is easy to grow into large trees. For this reason, there are many large, old specimens of this species in Japan. They are often regarded as sacred and have become landmarks that symbolize Shinto shrines, Buddhist temples, and local areas. For example, , which is around 2,000 years old, , which is around 1,500 years old, and , which is around 1,000 years old, are famous for their age.
In the Edo period, various double-flowered cultivars were produced and planted on the banks of rivers, in Buddhist temples, in Shinto shrines, and in daimyo gardens in urban areas such as Edo; the common people living in urban areas could enjoy them. Books from the period record more than 200 varieties of cherry blossoms and mention many varieties that are currently known, such as 'Kanzan'. However, this situation was limited to urban areas, and the main objects of hanami across the country were still wild species such as Prunus jamasakura (Yamazakura) and Oshima cherry.
Since Japan was modernized in the Meiji period, the Yoshino cherry has spread throughout Japan, and it has become the main object of hanami. Various other cultivars were cut down one after another during changes related to the rapid modernization of cities, such as the reclamation of waterways and the demolition of daimyo gardens. The gardener Takagi Magoemon and the village mayor of Kohoku Village, Shimizu Kengo, were concerned about this situation and preserved a few by planting a row of cherry trees, of various cultivars, along the Arakawa River bank. In Kyoto, Sano Toemon XIV, a gardener, collected various cultivars and propagated them. After World War II, these cultivars were inherited by the National Institute of Genetics, Tama Forest Science Garden and the Flower Association of Japan, and from the 1960s onwards were again used for hanami.
Since the beginning of the 21st century, the situation surrounding cherry blossom viewing in Japan has changed significantly. An invasive longhorn beetle, Aromia bungii, which is not native to Japan, is believed to have arrived in wooden packing materials used in international cargo, and was first confirmed in the country in 2012. This species has rapidly expanded its range across Japan, and its feeding damage has had devastating effects on cherry trees, forcing the removal of large branches or even the complete felling of many trees.
At the same time, the most popular cherry cultivar, Yoshino cherry, is increasingly being replaced for a variety of reasons. This cultivar is particularly susceptible to Witch's broom disease, and the Japan Flower Association had already ceased its distribution and sale by 2009. In addition, because it grows quickly into a large tree with a wide, spreading crown and extensive root system, it can damage surrounding pavement, extend branches into neighboring properties, and is generally unsuitable as a street tree in narrow urban spaces. Poor maintenance and aging have also led to reduced flowering in many trees, along with an increased risk of falling dead branches. As a result, there has been a growing trend to replace Yoshino cherry with 'Jindai-akebono', a cultivar originating from Jindai Botanical Garden, which has a similar flower shape, size, and overall tree form, but is more resistant to disease, remains smaller, and bears slightly deeper pink flowers. Another cultivar, 'Yoko', developed in Ehime Prefecture in 1981, is also spreading relatively quickly throughout Japan as an alternative. It is characterized by large, deep pink flowers and early blooming, features that clearly distinguish it from Yoshino cherry.
Every year, the Japanese Meteorological Agency (JMA) and the public track the as it moves northward up the archipelago with the approach of warmer weather, via nightly forecasts following the weather segment of news programs. Since 2009, tracking of the sakura zensen has been largely taken over by private forecasting companies, with the JMA switching to focus only on data collection that than forecasting. The blossoming begins in Okinawa in January and typically reaches Kyoto and Tokyo at the beginning of April, though recent years have trended towards earlier flowerings near the end of March. It proceeds northward and into areas of higher altitude, arriving in Hokkaido a few weeks later. Japanese locals, in addition to overseas tourists, pay close attention to these forecasts.
Most Japanese schools and public buildings have cherry blossom trees planted outside of them. Since the fiscal and school years both begin in April, in many parts of Honshu the first day of work or school coincides with the cherry blossom season. However, while most cherry blossom trees bloom in the spring, there are also lesser-known winter cherry blossoms (fuyuzakura in Japanese) that bloom between October and December.
The Japan Cherry Blossom Association has published a list of Japan's Top 100 Cherry Blossom Spots (), with at least one location in every prefecture.
Blooming season