A cherry blossom is the flower of any of several trees of genus Prunus, particularly the Japanese cherry, Prunus serrulata, which is called sakura after the Japanese (桜 or 櫻; さくら).
Cherry blossom is speculated to be native to the Himalayas. Currently it is widely distributed, especially in the temperate zone of the Northern Hemisphere including Japan, China, Korea, Europe, West Siberia, India, Canada, and the United States. Along with the chrysanthemum, the cherry blossom is considered the national flower of Japan.
Many of the varieties that have been cultivated for ornamental use do not produce fruit. Edible cherries generally come from cultivars of the related species Prunus avium and Prunus cerasus. Cherry blossom are also closely related to other Prunus trees such as the almond, peach, plum and apricot and more distantly to apples, pears and roses.
"Hanami" is the centuries-old practice of picnicking under a blooming sakura or ume tree. The custom is said to have started during the Nara Period (710–794) when it was ume blossoms that people admired in the beginning. But by the Heian Period (794–1185), cherry blossoms came to attract more attention and hanami was synonymous with sakura. From then on, in both waka and haiku, "flowers" (花 hana?) meant "cherry blossoms". 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 sakura trees, people had lunch and drank sake in cheerful feasts.