Rediscovery of Chamisso's type specimens of Hawaiian Psychotria (Rubiaceae, Psychotrieae) in the herbarium of the Natural History Museum, Vienna.

Between 1815 and 1818, Count Nikolai Romanzoff funded an expedition of the Russian brig Rurik . Besides their primary goal to discover the Northeast Passage, their aim was to collect scientific specimens, for which the botanist Adelbert von Chamisso and the entomologist Johann Friedrich von Eschscholtz were commissioned. On the Hawaiian Islands, they collected two unknown endemic species that Chamisso and Diederich Franz Leonhard von Schlechtendal later described as Coffeakaduana and C.mariniana , both now assigned to the large and complex genus Psychotria (Rubiaceae, Psychotrieae). The private herbarium of Chamisso is now preserved at the Komarov Botanical Institute, St. Petersburg (LE). In the late 1930s, their type collections of Psychotriakaduana and P.mariniana were sent out on loan for study, but got lost in transit during the aftermath of the Second World War. No extant original material was found during a subsequent revision of Hawaiian Psychotria and both species were consequently neotypified. These neotypes are superseded by the here-reported rediscovery of original material in the herbarium of Stephan Ladislaus Endlicher preserved at the Natural History Museum, Vienna (W) and these specimens are here designated as lectotypes. As both are rather fragmentary, the former neotypes are additionally designated as epitypes. In addition, some peculiarities and details of the expedition and its collections are noted.