This section is from the book "Commercial Gardening Vol3", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
The modern Cherry has been evolved from two more or less distinct species of Wild Cherry, both natives of the British Islands, and also found across Europe to the Himalayas. One species - the Prunus Cerasus or Cerasus vulgaris of botanists - is the Wild or Dwarf Cherry. It grows 15 to 20 ft. high, has reddish bark, slender drooping branches, and dark bluish-green serrated leaves, and clusters of pure-white flowers in May. The Morello, Duke, and Kentish Cherries are considered to have arisen from this. The variety " Bigarella" (or Cerasus duracina) is supposed to be the ancestor of the Bigarreau or Bigarron, and Heart Cherries. This distinction, however, is also claimed for the other wild species of Cherry (Prunus or Cerasus Avium), from which the "Geans " have also been obtained. Following the late Dr. Hogg's classification in the Fruit Manual, and quoting from the Editor's Practical Guide to Garden Plants, Cherries may be grouped into four principal classes.
These are round-headed trees with long, wavy, thin, and flaccid leaves, and more or less heart-shaped fruits with a tender and melting flesh. According to the colour of the flesh they are divided into (1) Black Geans and (2) Bed Geans. They grow best on the Cherry stock as a rule.
These resemble the Geans in habit and foliage, but have heart-shaped fruits, which are divided according to colour into (1) Black Hearts, and (2) White or Bed Hearts. They grow best on the Cherry stock as a rule.
The Duke Cherries have upright or spreading branches, with large and broad leaves. According to colour they are called (1) Black Dukes and (2) Red Dukes. They grow best on the Mahaleb stock as a rule.
These have long, slender, and drooping branches, with small and narrow leaves. According to colour of the fruits they are known as (1) Black Morellos and (2) Red or Kentish Morellos. They grow best on the Mahaleb stock as a rule.