In one approach, it contains only the genus Trimezia, which then includes the genera Neomarica, Pseudotrimezia and Pseudiris.

Names including "apostle" refer to the incorrect belief that plants do not flower until 12 or more leaves are present.

The outer tepals (sepals) are larger than the inner ones (petals); both may have brown-purple markings at the base.

Molecular phylogenetic studies have shown that although the tribe is monophyletic, the genera as traditionally used, based on morphological characteristics, are not.

[1] An alternative approach, retaining the traditional genera but with changed circumscriptions, was put forward in 2018; an additional new genus, Deluciris, was also created within the tribe.

[8] When Trimezia was distinguished from Neomarica prior to molecular phylogenetic studies, i.e. entirely on morphological grounds, some vegetative characters were considered diagnostic.

[10] Lovo et al. (2018) consider these characteristics to be among those distinguishing their circumscription of Neomarica from the other genera into which they divide the tribe.

[8] As of May 2019[update], the World Checklist of Selected Plant Families accepted about 80 species of Trimezia.