Edmund Russow and the typification of Sphagnum warnstorfii Russow (Sphagnum section Acutifolia, Sphagnaceae)

ABSTRACT Introduction. Edmund August Friedrich Russow was the sole author of three Sphagnum species and coauthor or author of the basionym for four others, three of which have been lectotypified. Russow described S. warnstorfii in 1888 but did not assign a type specimen in the protologue. However, he listed several locations where he had gathered the species. Material and typification. Various herbaria were searched for original material of Sphagnum warnstorfii that had been collected, identified and labelled by Russow prior to his compiling of the protologue for the species. Five specimens were found, which had been collected in 1887 at the localities mentioned in the protologue and labelled by Russow’s hand as ‘S. Warnstorfii m.’. A specimen collected from Techelfer (TU173562a) is designated as the lectotype because it is the only .one that bears the original signature of Russow. The other four specimens are cited as syntypes.