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

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 have not been located. 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.

Retrospective searching for poisonous plant vouchers.

Few published reports of plant poisoning, whether experimental or accidental, document vouchers. This can be rectified by retrospective location of vouchers through determination of a collaborating botanist or herbarium of deposit. An absolute voucher is referenced in the toxicology report. For a probable voucher the report does not identify an herbarium specimen, but the report and the specimen label or sheet agree on plant name, collector's name, collection date and place. A possible voucher is perhaps from the exposure lot, but was collected by the collaborating botanist at a somewhat earlier or later date than the exposure date. On the other hand, a supporting specimen was collected by the collaborating botanist but is not from the exposure lot. Vouchers and supporting specimens for some species of Asclepias tested for toxicity by CD Marsh and coworkers were found in the US National Herbarium at the Smithsonian Institution, Washington DC.

Poisonous plant vouchers.

Every published report of plant poisoning, whether experimental or accidental, should document plant identification. The essential elements are: complete botanical Latin name including species, specific epithet and author(s); name of the collaborating botanist who identified the plant; and herbarium and collection number of a voucher specimen from the exposure lot. Additional information to aid identification might include plant photographs, drawings, and descriptions.