Application of the name Lemna punctata G. Mey., the type of Landoltia Les & D. J. Crawford

Authors: Wiersema, John

Submitted to: Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/3/2014
Publication Date: 6/18/2014
Citation: Wiersema, J.H. 2014. Application of the name Lemna punctata G. Mey., the type of Landoltia Les & D. J. Crawford. Plant Biology. http://onlinelibrary.wiley.com/doi/10.1111/plb.12209/full.

Interpretive Summary: The new generic name Landoltia, which honors a longtime worker on the duckweed family, was proposed in 1999 for the species Landoltia punctata, a common aquatic weed formerly called Spirodela punctata that exists in much of the world. The increasingly common usage of the name Landoltia punctata depends on Lemna punctata, a name first applied in 1818 to a collection from South America that is now lost, leaving the interpretation of the name controversial. Usage of these names for this widespread weed has recently (in 2011) been challenged by someone whose actions, if unanswered, would change the names of two duckweed species. Such a change would make the generic name Landoltia unavailable. This report applies the international rules of nomenclature to argue against this new interpretation and support retention of the existing names. This work will be used by scientists, among whom agreement and standardized usage on scientific names is of considerable importance.

Technical Abstract: A recent (2011) attempt to change the previously designated type of the name of a duckweed species is discussed. Lemna punctata was first applied by Meyer in 1818 to a plant collected from South America, but original specimens no longer exist. A prior neotype designation associated this name with a species native to parts of Asia, Australia, and the Pacific, and widely introduced elsewhere, including South America. The species is generally treated by taxonomists in the genus Spirodela (either as S. punctata or the synonym S. oligorrhiza) or, more recently, as the sole member of the new (1999) genus Landoltia (as L. punctata). If accepted, this 2011 attempt to re-neotypify L. punctata would disrupt the names of two duckweed species as well as that of Landoltia. Nomenclatural arguments against accepting this new typification are provided, thereby supporting the continued usage of Landoltia in the sense intended by its original authors.