Tomentaurum G.L. Nesom is a monotypic genus native to Esto. Durango, Mexico. In the cladistic analysis of the Chrysopsidinae by Semple and Tebby (1999), Tomentaurum was consistently the sister group to Noticastrum. Semple (2006) noted and illustrated the quadruple pappus of N. nivea. The genus is assumed to be x=9, although no chromosome count has been published.