There are many different types and varieties of coffee trees on which coffee cherries grow.
The genus Coffea is a flowering tree. As science continues to discover new species, the classification continues to evolve. No one knows exactly how many species exist; So far, 124 different species of Coffea have been identified - 20 years ago, not even half that number was known.
Wild Coffea species are found mainly in Madagascar and Africa, but also in the Mascarene Islands, The Comoros, parts of Asia as well as in Australia.
Only the species C. arabica and C. canephora (commonly called Arabica and Robusta) are widely cultivated for commercial use. They represent approximately 99 percent of all the global production. It is believed that C. arabica emerged on the border of Ethiopia and South Sudan from a cross between C. canephora and C. eugenioides. Some countries also produce small quantities of C. liberica and C. excelsa for the domestic market.
Arabica and Robusta varieties
There are many cultivars of Arabica. The way in which it spread around the world is unknown and often contradictory, but of the thousands of varieties native to Ethiopia and South Sudan, very few left the continent. They first came to Yemen and from there to other countries.
These trees are commonly referred to as typica - "ordinary" coffee. The Typica trees planted in Java are the genetic ancestors of those trees that have spread worldwide. Bourbon, also one of the earliest known varieties, was created by mutating a typica that appeared on Réunion Island (then Île Bourbon) between the mid-18th and late 19th century. Today, most varieties are natural mutations or mutation breeds of the two varieties. Coffea canephora is native to West Africa. Seedlings from the Democratic Republic of the Congo (thje Belgian Congo) were also planted in Java. From there it spread to almost all Arabica-growing countries.
There are several varieties of this species, but they are commonly referred to simply as Robusta. In addition, Arabica and Robusta were planted together to create new varieties. The appearance and aroma of coffee are influenced by many factors, including soil, sun, rain, wind, pests and diseases. Many varieties are genetically similar but carry regionally different names. This makes it difficult to accurately map the distribution of Arabica and Robusta.
The Coffee Book
© Dorling Kindersley Publishing Company GmbH, Munich, May 2017