This refers to the fact that most species can be grown in moist habitats for part of the year.

(Annales des Sciences Naturelles; Botanique).

[6] It has 45 species, which are widely distributed in the Northern Hemisphere.

[3] It is a group that has been recognized with few changes since Dykes's 1913 monograph on the genus Iris.

Lawrence (1953), Rodionenko (1987) and then Mathew (1989) all tried to modify the group.