Abstract
Available information on the typification of the name Ranunculus rionii in the literature is scarce and mis-leading. Previously claimed type collections indicate Lagger as the collector, but the protologue discusses only the specimens collected by Rion.
Original material for the name is identified, the locality of the type collection is specified, Lagger's way of writing herbarium labels for his type specimens is described, the history of the discovery of R. rionii is reviewed, and the name is lectotypified.