Because pappi of Nothocalaïs taxa vary from capillary bristles to aristate scales, the species were earlier assigned to either Agoseris or Microseris. The totality of morphologic evidence supports the unity of the genus, as well as its segregation from Agoseris and Microseris (K. L. Chambers 1955, 1957). According to recent phylogenetic studies based on chloroplast DNA (R. K. Jansen et al. 1991b; J. Whitton et al. 1995), Nothocalaïs is most closely related to Uropappus and Agoseris, the three genera together comprising a clade sister to Microseris.