Editing Rubiaceae (section)

=== Associations with other organisms ===
The genera ''[[Anthorrhiza]]'', ''[[Hydnophytum]]'', ''[[Myrmecodia]]'', ''[[Myrmephytum]]'', and ''[[Squamellaria]]'' are succulent [[epiphyte]]s that have evolved a [[mutualism (biology)|mutualistic]] relationship with ants. Their [[hypocotyl]] grows out into an ant-inhabited tuber.<ref name="Kapitany2007"/> Some shrubs or trees have ant holes in their stems (e.g. ''[[Globulostylis]]'').<ref name="Verstraete2013b"/> Some Rubiaceae species have domatia that are inhabited by mites (viz. [[acarodomatia]]; e.g. ''[[Plectroniella armata]]'').<ref name="Tilney2012"/>

An intimate association between bacteria and plants is found in three rubiaceous genera (viz. ''[[Pavetta]]'', ''[[Psychotria]]'', and ''[[Sericanthe]]'').<ref name="Lemaire2011"/> The presence of endophytic bacteria is visible by eye because of the formation of dark spots or nodules in the leaf blades. The endophytes have been identified as ''[[Burkholderia]]'' bacteria. A second type of bacterial leaf symbiosis is found in the genera ''[[Fadogia]]'', ''[[Fadogiella]]'', ''[[Globulostylis]]'', ''[[Rytigynia]]'', and ''[[Vangueria]]'' (all belonging to the tribe [[Vanguerieae]]),<ref name="Verstraete2011"/><ref name="Verstraete2013a"/><ref name="Verstraete2013c"/> and in some species of ''[[Empogona]]'' and ''[[Tricalysia]]'' (both belonging to the tribe [[Coffeeae]]),<ref name="Verstraete2023"/> where ''[[Burkholderia]]'' bacteria are found freely distributed among the mesophyll cells and no leaf nodules are formed. The hypothesis regarding the function of the symbiosis is that the endophytes provide chemical protection against herbivory by producing certain toxic secondary metabolites.<ref name="Sieber2015"/>