Mislabelling of Salvinia plants in trade in the EPPO region
Incorrect labelling of plants in trade and misidentification are widespread and may be caused by negligence or wilful disrespect of regulations. Mislabelling may consist of simple misspelling of names or considering a variety as a true species, using synonyms or preferring a name that sounds nice or a name that customers are familiar with. Salvinia molesta (Salviniaceae: EPPO A2 List), is a good example of an aquatic plant that has long been traded in the EPPO region and is often labelled as the more pleasant-sounding Salvinia natans or just simply Salvinia. The plant can be traded as an individual species/commodity by itself or in a mixture of decorative floating plants. In the more temperate areas of the EPPO region which experience cold winters, S. molesta is considered unlikely to cause important negative effects; however, it is known to be a serious invasive species in tropical regions, clogging waterways and entire irrigation systems. Inspections and a targeted survey of Salvinia plants in trade in the Netherlands were performed and additional material was obtained from wild sources in South Africa, Hungary and the USA. Specimen identification was verified by comparison with the herbarium collection at Naturalis Biodiversity Center in Leiden and with the sequences available in NCBI GenBank database. Results showed that there are reliable tools to distinguish these Salvinia species and avoid mislabelling. Sterile samples of S. molesta and S. auriculata can be reliably distinguished based on cpDNA data, thereby enabling the identification of mislabelled Salvinia plants that are difficult to distinguish on macromorphological criteria. Mislabelled plants of S. minima and S. natans can be easily distinguished by the macromorphological features of the hairs on the upper side of the floating leaves.
Sources
Van Valkenburg JLCH, Piet LF, Boer E (2023) Salvinia plants in trade: what species are we actually talking about? EPPO Bulletin (early view), https://doi.org/10.1111/epp.12909