All in all, there are about 100 different varieties of the species Coffea. The coffee plant grows wild in Ethiopia, from where it originates. Three species are cultivated commercially – Arabian coffee (Coffea arabica), Liberian coffee (Coffea libericadanius) and robusta coffee (Coffea canephora). Some other species are grown locally, mainly in Africa.
Arabian coffee is the most important variety and is considered to have the best flavour, robusta beans have a higher caffeine content and some, high quality, beans are used in special espresso varieties and are widely used in several coffee-exporting countries.
Coffee contains the stimulant caffeine.