Henning, T.; Quandt, D.; Grosse-Veldmann, B.; Monro, A.; Weigend, M.

Weeding the Nettles II: A Delimitation of “Urtica dioica L.” (Urticaceae) Based on Morphological and Molecular Data, Including a Rehabilitation of Urtica gracilis Ait.

. Phytotaxa 2014, 162, 61–83.