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Rare Jackson 2/157 and K7 Coffee Varieties | Over 60 Species of Coffee Plants Worldwide

Published: 2026-01-27 Author: FrontStreet Coffee

Last Updated: 2026/01/27, For professional coffee knowledge sharing and more coffee bean information, please follow Coffee Workshop (WeChat official account: cafe_style). We know that coffee beans come in many varieties. Under the three main categories, Arabica alone can be divided into numerous coffee varieties. Common ones include Typica, Bourbon, Geisha, Caturra, Catuai, and many more. Today, FrontStreet Coffee would like to introduce two relatively rare coffee varieties to you.

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For more coffee bean information, please follow Coffee Workshop (WeChat official account: cafe_style)

Exploring Rare Coffee Varieties: Jackson 2/157 and K7

We know that there are many varieties of coffee beans. Among the three major varieties, Arabica alone can be divided into numerous coffee varieties. Common ones include Typica, Bourbon, Geisha, Catuai, Catimor, and so on. Today, FrontStreet Coffee would like to introduce two relatively rare coffee varieties: Jackson 2/157 and K7.

The genus Coffea includes over 120 species, typically opposite-leaved, evergreen shrubs or small trees with horizontal branches. They contain paired seeds, with one flat side and the other with a groove (yes, that's the coffee bean!). Most plants in the genus Coffea prefer tropical forest habitats. There are approximately 60 species of Coffea plants worldwide, but only 25 are artificially cultivated for coffee production, with only 4 used as commercial coffee: Coffea liberica, Coffea canephora, Coffea arabica, and Coffea dewevrei.

Jackson

A strong, high-yield variety commonly found in Rwanda and Burundi.

In the early 20th century, a coffee farmer named Jackson in Mysore, India, discovered coffee trees resistant to coffee leaf rust disease on his farm (this variety's resistance has been lost and is now susceptible to leaf rust). The variety was named after the discoverer.

In the 1920s, seeds from these trees were sent to research stations in Kenya and Tanzania. These original trees became the Jackson variety commonly found in Rwanda (literature suggests this variety may have come from the germplasm collection in Mulungu, Democratic Republic of Congo in the 1930s, or may have been brought to Rwanda by Kenyan immigrants in the late 1940s).

The varieties Jackson, Kent, Coorg, and Mysor all come from the same region in India. Coffee from this region was most likely developed from seeds that Baba Budan brought from Yemen to India in 1670. The closest genetic tests confirm that Jackson has a genetic relationship with the Bourbon family.

K7

Resistant to coffee leaf rust and coffee berry disease, commonly found in Kenya and Tanzania.

K7 is renowned for its resistance to rust and coffee berry disease and is widely used in modern breeding projects in Kenya and Tanzania.

K7 is the fifth-generation variety selected from the original population by the Scott Agricultural Laboratory in Kenya (see SL28 for the history of the Scott Laboratory) in 1936. Currently, it is still widely cultivated in Kenya.

According to P.A. Jones, an agricultural officer at the Kenya Coffee Research Station in the 1950s, K7 was one of two trees selected by Mr. R.H. Walker in 1936 from French missionary variety coffee trees at Legget Estate in Muhoroni (for more information on French missionary varieties, see SL34). One of these varieties was later named K7 and apparently was immune to coffee leaf rust for several years (this variety no longer has resistance).

The closest genetic tests confirm that Jackson has a genetic relationship with the Bourbon family.