Rytigynia is a genus of flowering plants in the family Rubiaceae. It is found in tropical and southern Africa. The genera Rytigynia and Fadogia form a strongly supported clade but neither of these genera is monophyletic.

Distribution

Rytigynia is found in Tropical Africa. R. senegalensis and R. umbellulata are the two most widespread species and they are found from Senegal to Sudan to Botswana. R. celastroides has the southernmost distribution and occurs as far south as KwaZulu-Natal. However, most species are more restricted in distribution area and they are often found in either West or East Africa. Half of the species is even endemic to one country. One-third of all Rytigynia species is found in Tanzania, and many of them are endemics.

Bacterial leaf symbiosis

Endophytic bacteria are housed in the intercellular space of the leaf mesophyll tissue. The presence of these bacteria can only be microscopically ascertained. The bacteria are identified as Burkholderia, which is a genus that is also found in the leaves of other Rubiaceae species. The hypothesis is that these endophytic bacteria provide chemical protection against insect herbivory.

Species