Pimenov, M. G., Kljuykov, E. V. & Ostroumova, T. A.: Reduction of Notopterygium to Hansenia (Umbelliferae). — Willdenowia 38: 155–172. — ISSN 0511-9618; © 2008 BGBM Berlin-Dahlem. doi:10.3372/wi.38.38110 (available via  http://dx.doi.org/)

Morphological analysis, including detailed fruit structure investigation, confirms a hypothesis recently proposed on the basis of a phylogenetic analysis of DNA sequence data, on a close relationship between the mainly Siberian genus Hansenia and the endemic Chinese genus Notopterygium. Therefore the species of Notopterygium are transferred to the previously unispecific Hansenia and five new nomenclatural combinations are validated. As a result, Hansenia comprises six species, distributed from the mountains of S Siberia across Mongolia and N China to the SW Chinese provinces of Sichuan and Yunnan.