Throughout history, people have told many stories about where coffee came from. But we know that the wild coffee plant (Coffea arabica) originally grew in Ethiopia. People found it around AD 850. The story of Robusta coffee is more recent. It seems the first time people moved and grew these plants was around 1870 in the Congo area. So, even though their stories aren't exactly the same, both species of coffee come from the forests of Africa.

So, both coffee and humans started their journeys in Africa. The forests in Ethiopia and South Sudan are where Arabica coffee began. This is also where early humans started to explore the world. Arabica coffee today comes from trees in the Rift Valley forests, a remarkable part of Earth's history. Some of these trees still grow wild today, as botanists have reported.

Humans took coffee plants to other parts of the world. The spreading of Arabica coffee began in the 8th century when seeds were taken from Ethiopia to Yemen. There, people grew coffee until about the end of the 14th century. Then, coffee spread to far-off places like India, Sri Lanka, Java, and Indonesia, where people started large coffee farms. In the early 17th century, coffee came to Europe, first brought by a Dutch trader in 1616. They grew coffee plants in the Amsterdam Botanical Garden and later in other places. Some coffee plants were even given as gifts to King Louis XIV of France. This started coffee farming in French colonies and soon in Spanish and British ones too. Coffee farming spread to many parts of the world with warm climates.

Robusta coffee spread from Central Africa, near the Lomani River, to other places. It was brought from the Belgian Congo (now the Democratic Republic of Congo) to Java via Brussels. Then, new plants were grown in places like India, Uganda, and Ivory Coast. People started using local plants for farming in different African countries. This helped spread Robusta coffee to new places before it finally reached the Americas around 1912.

Even today, new types of wild coffee are found in African forests. And new coffee varieties are being developed in many tropical regions. Programs in Central America, Colombia, Brazil, Ivory Coast, and Kenya focus on making coffee plants that produce a lot, resist pests and diseases (especially for Arabica), adapt well to different climates, and have unique tastes when possible.

Botanical origin and geographical distribution

The Coffee Plant

For botanists, any tropical plant belonging to the Rubiaceae family that produces coffee beans is called a "coffee tree." Since the 16th century, botanists have described over 100 coffee species, and this number has increased significantly since the Coffea genus was created. "True coffees" belong to the Coffeeae tribe, which includes two genera: Psilanthus and Coffea. The main difference between these two groups lies in the structure of their flowers. The Coffea genus has a long style and a medium-length corolla tube with protruding anthers, while the Psilanthus genus has a short style and a long corolla tube with enclosed anthers. Coffee plants can vary in appearance from small perennial bushes to sturdy, woody trees, and their fruits have a distinct structure. Each fruit is a drupe with two seeds, each having a characteristic deep groove in the ventral part, known as the "coffeanum suture".

Evolutionary History

The main Coffea species, including the commercially important Arabica and Robusta, seem to have originated in the central region of Africa. Initially, Arabica was a shrub that grew in the undergrowth of forests in southwest Ethiopia and northern Kenya, at altitudes between 1300 and 2000 meters. It was only relatively recently, after various botanical explorations throughout the 20th century, that the origin of C. arabica was officially recognized. In 1999, molecular and cytogenetic analyses revealed that Arabica resulted from the natural hybridization of two ecotypes related to C. eugenioides and C. canephora species. The low genetic difference found between the genomes of C. arabica and its parent species suggests that Arabica arose from a very recent evolutionary event between 10,000 and 50,000 years BC.

The species C. canephora originated in the humid lowland forests of tropical Africa. Initially, two main genetic types were identified: Kouillou and Robusta. The Kouillou type was a small group with low diversity, with one variety known as "Conilon," widely cultivated in Brazil. The Robusta type, on the other hand, was the most significant and included two groups: Congolese (from Central Africa) and Guinean (from Côte d'Ivoire and Guinea). Each group had distinct differences in morphology, growth habits, and ecological adaptability. Subsequent molecular studies further differentiated each group into seven subgroups.

Despite the wealth of information gathered, the complete evolutionary history of Coffea species remains incomplete. However, recent advances in genomic technologies applied to coffee plants have provided additional insights into their evolution.

Geographic Distribution

The original geographic distribution of the Coffea genus is limited to tropical humid regions of Africa and islands in the West Indian Ocean. Molecular analyses of Coffea species have shown a strong correlation between their evolutionary origins and their geographic distribution in four major intertropical forest regions: West and Central Africa, East Africa, and Madagascar, where the species originated. Over the last 15 years, the number of Coffea species recorded in different countries has revealed three main hotspots of species diversity located in Madagascar, Cameroon, and Tanzania. Despite increased deforestation in these regions, there are still records of new species in other countries along the intertropical region of Africa.

While coffee species can be found from sea level up to 2300 meters above, most species (67%) are adapted to altitudes below 1000 meters. Some species, like C. canephora, Coffea liberica, Coffea salvatrix, Coffea eugenioides, or Coffea brevipes, have a broad distribution in elevated regions, ranging from lowlands up to 1500 meters, while others are mainly found in narrow altitude ranges. C. arabica, for example, thrives in altitudes between 800 and 2000 meters. Most species with wide distributions in mainland Africa (such as C. canephora, C. eugenioides, and C. liberica) are commonly found in humid habitats characterized by evergreen or gallery forests. In contrast, other species like Coffea congensis, Coffea racemosa, or Coffea pseudozanguebariae have specific adaptations to habitats with particular soil and climate conditions.