Panicum riparium H. Scholz – a neoindigenous species in Europe?

Abstract

P. riparium was newly described as a neoindigenous species from Germany in 2002. The characteristics of the species are critically examined and compared with those of P. capillare. A map shows the currently known distribution of P. riparium in Europe, (fig. 2). Historical herbarium specimens dating back to the 18th century were found. A comparison of the characteristics confirm the broad agreement with American plants. A taxonomic clarification of the American taxa of the P. capillare group leaves no doubts: The characteristics of P. riparium are largely identical to those of P. barbipulvinatum Nash. P. riparium is consequently to be placed in the synonymy of this species.