Neotypification of Cistanche tubulosa (Schenk) Wight ex Hook.f.: a name applied to a widely distributed, polyphyletic group of plants

The name Cistanche tubulosa s.l. is used from Africa and the Middle East to South and Central Asia and China, however this name is applied to plants that have been shown to comprise a polyphyletic group. Maintaining the use of this species name across distinct lineages is untenable, but inclusion of a type specimen in further analyses is needed to correctly apply names to revised taxa and to evaluate the recent decision to place the name in synonymy under the name C. tinctoria (Forssk.) Beck. Therefore, we proposed a neotype for Cistanche tubulosa (Schenk) Wight ex Hook.f. We contextualise the relevant taxonomy with a broader discussion on taxonomic challenges in the genus Cistanche in which several species are traded for herbal medicine, rare, or are of conservation concern.