Gaertnera is a genus of flowering plants in the family Rubiaceae. There are at least 85 species distributed across the Old World tropics from Africa to Asia.

Plants in this genus are variable in appearance and biology. Most all are regional endemics, plants limited to a small geographical area and narrowly adapted to local conditions. Most grow in moist forest habitat.

These are generally woody plants with clusters of white, pink, or red flowers and purple-black fruits. Some species are distylous, with plants having one of two flower morphs. Other species are dioecious, with plants having either male or female flowers. Dioecious species are generally found in Southeast Asia.

...