Taxonomy_of_the_coffee_plant

Botanists have described 610 genera with around 13.000 species in the Rubiaceae family. The Rubiaceae
have a cosmopolitan distribution (see red fields on the map). Cosmopolitan is a biogeographical term and
means that species of this family are found across all or most of the world in their respective appropriate
habitats. These habitats are mainly in warmer places of the tropics and the subtropics with few exceptions
growing in the temperate zone or even in colder climates.
The Rubiaceae are morphologically easily recognizable as a coherent group by a combination of characters
or traits: opposite leaves that are simple and entire, interpetiolar stipules, tubular sympetalous
actinomorphic corollas and an inferior ovary. Regarding the meaning of these traits, we will discuss them in
more detail in a following section. The most common growth form in this family are shrubs, but also trees,
lianas or herbs are described. In our latitudes members of this family grow as herbs, e.g. sweetscented
bedstraw is a flowering perennial plant that only grows during the summer, while it overwinters as seed.
Rubiaceae was first described by French botanist Antoine-Laurent de Jussieu, who named and grouped
plants of this family in his main work titled “Genera plantarum”. His grouping of species in this family was
based on correlating traits, e.g. opposite leaves and stipules. This interlinking correlation of different traits
was also an advancement compared to the system of Carl from Linné.
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