Presence, morphological and ultrastructural diversity of orbicules or Ubisch bodies are investigated in 129 species (99 genera). covering the families Gentianaceae, Rubiaceae, Apocynaceae s.l. (met. Asclepiadaceae), and the segregated Loganiaceous families (Loganiaceae s.str., Strychnaceae, Gelsemiaceae, Geniostomaceae, and the Loganiaceae tribe Potalieae which is included in Gentianaceae), with light microscopy, scanning electron microscopy and transmission electron microscopy. Of the 129 species investigated, 95 species (73 genera), covering all the families included in Gentianales, possess orbicules. Orbicule types were defined, based on the observed morphological and ultrastructural variations of the present orbicules. The typology follows the treatment of orbicule types described for the rubiaceous subfamilies Cinchonoideae and Ixoroideae. No intraspecific variation has been observed in Gentianales. all investigated specimens of one species are characterised by the same orbicule type. The systematic value of these types has been tested by comparison with the most recent classifications in Gentianales. We can conclude that orbicules are a common feature in Gentianales and that orbicule characteristics can be useful to clarify relationships between genera. Comparable with the conclusions on the systematic application of orbicule characteristics in the Rubiaceous subfamilies Cinchonoideae and Ixoroideae, we suggest that orbicules can be useful in Gentianales at a tribal level.