The Wild Cherry Prunus avium is widely planted in new woodlands, parks, gardens and streets. It has ‘single’ flowers. Note that a ‘single’ flower has 5 petals, a ‘semi-double’ flower has 2 rows of 5 petals and a ‘double’ has 3 or more rows. ‘Double’ flowers arise when some of the rows of anthers  become petals. The Wild Cherry cultivar ‘Plena’ has white ‘double’ flowers. Each flower has up to 30 petals.

Wild Cherry flowers
Wild Cherry cultivar 'Plena'

Japanese Flowering Cherries are a large group of cultivars that were bred in Japan from the 15th Century and were known collectively as Sato Zakura (village cherries). Their taxonomic origin is unclear but one of their parents is believed to be the Japanese Cherry (Prunus serrulata), native to northern and central China, Korea and Japan. The flowering cherries were introduced to Britain as early as 1822. They bear white or pink flowers in spring. There are more than 20 cultivars on sale in Britain. Some examples are shown here.

‘Kanzan’ has pink ‘double’ flowers in spring before the leaves. Each flower has 25 to 28 petals. 

'Kanzan' Cherry tree
'Kanzan' Cherry flower

‘Amanogawa’ has a vertical shape and ‘semi-double’ pale pink flowers. 

'Amanogawa' Cherry tree
'Amanogawa' Cherry flower

‘Shirofugen’ has pink/white ‘double’ flowers and is one of the last to flower in spring.  Each flower has 25 or more petals. ‘Tai Haku’, also known as the Great White Cherry, has very large, white, ‘single’ flowers and big leaves. 

'Shirofugen' Cherry flower
'Tai Haku' Cherry flower