Previously one of three families in the order Primulales, it underwent considerable generic re-alignment once molecular phylogenetic methods were used for taxonomic classification.

In this new classification of the Angiosperm Phylogeny Group, each of the Primulales families was reduced to the rank of subfamily of Primulaceae s.l.

Leaf arrangement is typically alternate but some are opposite or whorled, and there is generally a rosette at the base of the stem.

[a][9] Some earlier authors[clarification needed] attributed the name to Ventenat (1799), as Primulaceae Vent.,[10] who described the Primulacées,[11] but Batsch had precedence.

[2] Linnaeus (1753) placed Primula and related primuloid genera in the Hexandria Monogynia (six stamens one pistil) in his sexual classification based on reproductive characteristics.

[12] Jussieu arranged Linnaeus' genera in a hierarchical system of ranks based on the relative value of a much wider range of characteristics.

[15] The most complete treatment of the Primulaceae family, with nearly 1,000 species arranged into 22 genera, was by Pax and Knuth in 1905 in the Engler system.

[16][17] Many systems since have lacked consistency, but generally recognised two major groups as either tribes or subfamilies, the Lysimachieae and Primuleae (the Androsaceae of Pax and Knuth), with the largest genera being Primula, Lysimachia and Androsace.

[21][22][5] In the first consensus taxonomic classification, the Angiosperm Phylogeny Group (APG 1998), these proposals were recognised by including Primulaceae within Ericales, as Eudicots, forming one of three clades in the Asterids (Asteridae).

At that time Primulaceae was considered to consist of nine tribes (Primuleae, Androsaceae, Ardisiandreae, Lysimachieae, Glauceae, Anagallideae, Corideae, Cyclamineae, and Samoleae).

[10] Notably, Lysimachieae and three smaller tribes, Corideae, Cyclamineae and Ardisiandreae, were transferred to Myrsinaceae, and Samoleae to Theophrastaceae.

[27] These transfers, to preserve monophyly at the family level essentially left two tribes remaining in Primulaceae, the Primuleae and Androsaceae, with about 15 genera sharing a number of common characteristics.

[28] This restricted Primulaceae sensu stricto (s.s.) consisted of three groups: The Primulae, including Primula, the largest genus; the Androsaceae, including Androsace, the second largest genus; together with a small third group containing Soldanella, Hottonia, Omphalogramma and Bryocarpum.

The decision to treat all genera as a single family was based on the observation that the new circumscriptions had little in the way of apomorphies, but the entire group had numerous synapomorphies and were easy to recognise.

The divergence between Theophrastoideae and Primuloideae-Myrsinoideae at 70 mya represents a vicariant event between the Neotropics and the Palearctic in the case of the latter.

[30] The three former families of the Primulales, together with the segregated Maesaceae, have been re-circumscribed into the broadly defined Primulaceae sensu lato (s.l.)

The two uniting features of this family are a free central placenta and one stamen opposite each of the corolla lobes.

The flowers are small, with short tubules and semi-inferior ovary, arranged in axillary or terminal racemes, or in panicles.

Maesa has about 100 species, and is distributed in both tropical and subtropical regions of the Old World, ranging from East Africa to Japan.

[30] Within the Myrsinoideae, the genera represented by the restricted Myrsinaceae s.s., prior to the transfers from the then Primulaceae, form a distinct clade.

These two (or one) tribes represent the remaining genera in Primuloideae (Primulaceae s.s.) following redistribution among the Primulales on molecular grounds.

Previously it formed its own tribe, Samoleae within Primulaceae s.s., and in some systems, its own family, Samolaceae, but was subsequently transferred to Theophrastoideae.