The series was first classified by Ludwig Diels in 'Die Natürlichen Pflanzenfamilien' (Edited by H. G. A. Engler and K. Prantl) in 1930.

It was further expanded by George Hill Mathewson Lawrence in Gentes Herb (written in Dutch) in 1953.

[2] It has been theorised that the formation of the ice caps during the last ice age, led to the split of Iris tridentata from other forms in North America.

[3] Most have small standards and violet-blue flowers,[2][4] with darker veins on the large falls.

[5] They prefer lime-free soils and moist conditions.