SummaryA new combination, Conocliniopsis grossedentata, in Conocliniopsis R.M.King & H.Rob. (Compositae: Eupatorieae: Gyptidinae) is provided. An earlier assessment of Prince Maximilian Wied-Neuwied’s collections (sent by Martius to Colla), proposed that Colla’s Eupatorium grossedentatum was a new synonym of Lourteigia ballotifolia (Kunth) R.M.King & H.Rob., a Colombian endemic. A critical assessment of Wied’s collection has indicated that the material, collected in Brazil near the Bahian coast, on the banks of the Rio Belmonte (= Rio Jequitinhonha), is conspecific with the plant more usually known as Conocliniopsis prasiifolia (DC.) R.M.King & H.Rob. Colla’s name pre-dates that of de Candolle’s Conoclinium prasiifolium, the basionym of Conocliniopsis prasiifolia; a new combination is necessary. A full synonymy of Conocliniopsis grossedentata is provided, types indicated, and other issues discussed.